Trial Outcomes & Findings for Gestational Weight and Incentive Research Study (NCT NCT03834194)

Last Updated: 2023-08-08

Results Overview

At 32 weeks gestation participants will be asked to offer insight into program acceptability in each condition, as well as satisfaction to the program in general by answering an internet-based survey, that was developed for this study (not a standardized scale). The investigators will examine participants' survey responses regarding participants' satisfaction of the program (items are scored on a scale from 1 to 5, with 5 being the most positive).

Recruitment status

COMPLETED

Study phase

Target enrollment

40 participants

Primary outcome timeframe

Up to 32 weeks

Results posted on

2023-08-08

Participant Flow

Participant milestones

Participant milestones
Measure	Lottery + Monthly Weight Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Overall Study STARTED	4	5	5	5	5	5	5	5
Overall Study COMPLETED	3	4	4	5	5	4	5	5
Overall Study NOT COMPLETED	1	1	1	0	0	1	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Gestational Weight and Incentive Research Study

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Lottery + Monthly Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Total n=39 Participants Total of all reporting groups
Age, Continuous	24.5 years n=5 Participants	27.2 years n=7 Participants	29.6 years n=5 Participants	26.5 years n=4 Participants	25.6 years n=21 Participants	25.4 years n=8 Participants	29.2 years n=8 Participants	29.4 years n=24 Participants	29.1 years n=42 Participants
Sex: Female, Male Female	4 Participants n=5 Participants	5 Participants n=7 Participants	5 Participants n=5 Participants	5 Participants n=4 Participants	5 Participants n=21 Participants	5 Participants n=8 Participants	5 Participants n=8 Participants	5 Participants n=24 Participants	39 Participants n=42 Participants
Sex: Female, Male Male	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	1 Participants n=8 Participants	0 Participants n=24 Participants	3 Participants n=42 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	3 Participants n=5 Participants	4 Participants n=7 Participants	5 Participants n=5 Participants	5 Participants n=4 Participants	5 Participants n=21 Participants	5 Participants n=8 Participants	4 Participants n=8 Participants	5 Participants n=24 Participants	36 Participants n=42 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Race (NIH/OMB) Black or African American	2 Participants n=5 Participants	2 Participants n=7 Participants	4 Participants n=5 Participants	4 Participants n=4 Participants	4 Participants n=21 Participants	3 Participants n=8 Participants	2 Participants n=8 Participants	3 Participants n=24 Participants	24 Participants n=42 Participants
Race (NIH/OMB) White	1 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	1 Participants n=21 Participants	2 Participants n=8 Participants	2 Participants n=8 Participants	2 Participants n=24 Participants	10 Participants n=42 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	2 Participants n=42 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	1 Participants n=8 Participants	0 Participants n=24 Participants	3 Participants n=42 Participants
Body Mass Index category (proportion with overweight and obesity)	2 Participants n=5 Participants	3 Participants n=7 Participants	3 Participants n=5 Participants	3 Participants n=4 Participants	3 Participants n=21 Participants	2 Participants n=8 Participants	5 Participants n=8 Participants	1 Participants n=24 Participants	22 Participants n=42 Participants

PRIMARY outcome

Timeframe: Up to 32 weeks

Outcome measures

Outcome measures
Measure	Lottery + Monthly Weight n=3 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=4 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Intervention Satisfaction Observed From Follow-up Survey How much would you recommend using an e-scale for managing GWG to a friend?	5 units on a scale Interval 5.0 to 5.0	4.25 units on a scale Interval 3.0 to 5.0	4.25 units on a scale Interval 2.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0	4.75 units on a scale Interval 4.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0
Intervention Satisfaction Observed From Follow-up Survey How much would you recommend using a fitness tracker for managing GWG to a friend?	4.67 units on a scale Interval 4.0 to 5.0	3.5 units on a scale Interval 2.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	4.4 units on a scale Interval 2.0 to 5.0	4.25 units on a scale Interval 3.0 to 5.0	4.6 units on a scale Interval 4.0 to 5.0	4.4 units on a scale Interval 3.0 to 5.0
Intervention Satisfaction Observed From Follow-up Survey How much would you recommend setting a weight gain goal for managing GWG to a friend?	4.67 units on a scale Interval 4.0 to 5.0	4.25 units on a scale Interval 3.0 to 5.0	4.5 units on a scale Interval 3.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	4.4 units on a scale Interval 3.0 to 5.0	4.75 units on a scale Interval 4.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0	4.6 units on a scale Interval 4.0 to 5.0
Intervention Satisfaction Observed From Follow-up Survey How much would you recommend setting a physical activity goal for managing GWG to a friend?	4 units on a scale Interval 3.0 to 5.0	4.25 units on a scale Interval 3.0 to 5.0	4.5 units on a scale Interval 3.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	5 units on a scale Interval 5.0 to 5.0	4.25 units on a scale Interval 3.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0	4.8 units on a scale Interval 4.0 to 5.0

PRIMARY outcome

Timeframe: Up to 36 weeks

The number of participants initially recruited for the study will be closely monitored.

Outcome measures

Outcome measures
Measure	Lottery + Monthly Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Recruitment Yields Observed From Enrollment Survey	4 Participants	5 Participants	5 Participants	5 Participants	5 Participants	5 Participants	5 Participants	5 Participants

PRIMARY outcome

Timeframe: Up to 36 weeks

The number of participants stayed in the study within the time frame of the study will be closely monitored.

Outcome measures

Outcome measures
Measure	Lottery + Monthly Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Program Retention Observed From Enrollment and Followup Surveys	3 Participants	4 Participants	4 Participants	5 Participants	5 Participants	4 Participants	5 Participants	5 Participants

SECONDARY outcome

Timeframe: Up to 36 weeks

At all measurement visits, weight will be recorded in kilograms on a calibrated research-grade scale. Weight will be measured on a calibrated digital scale in duplicate, with the participant wearing light clothing and no shoes. While we will obtain the mother's weight at baseline, we will also obtain self-reported preconception weight (before the last menstrual period). We will calculate the participant's GWG goal based on self-reported preconception BMI. The difficulty of anticipating when a final weight should be obtained to capture the fullest extent of GWG was considered, and we elected to use an approach that afforded two possible weights that would be available for analytic purposes. The Week 36 weight will be the primary outcome except for mothers who deliver prior to 36 weeks, in which case we will use the Week 32 weight.

Outcome measures

Outcome measures
Measure	Lottery + Monthly Weight n=3 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=4 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Gestational Weight Gain Observed From Weight Recorded at Baseline and up to 36 Weeks	13.2 kilograms gained Interval 10.0 to 18.0	6.8 kilograms gained Interval 0.9 to 11.2	8.4 kilograms gained Interval -3.7 to 14.2	9.4 kilograms gained Interval 8.1 to 11.2	9.6 kilograms gained Interval -2.1 to 20.1	8.9 kilograms gained Interval -0.2 to 13.3	11.8 kilograms gained Interval 3.4 to 18.8	11.8 kilograms gained Interval 6.9 to 15.0

SECONDARY outcome

Timeframe: Up to 36 weeks pregnancy

We will evaluate whether participants' final gestational weight gain at Week 32 or Week 36 pregnancy would be under, within, or above IOM's recommendation. The Week 36 weight will be the primary outcome except for mothers who deliver prior to 36 weeks, in which case we will use the Week 32 weight. This is to determine the effect of the intervention on prevention of excess gestational weight gain.

Outcome measures

Outcome measures
Measure	Lottery + Monthly Weight n=3 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=4 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 Participants Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=4 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 Participants Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Number of Participants With Gestational Weight Gain Within IOM Recommendation	2 Participants	2 Participants	0 Participants	1 Participants	2 Participants	2 Participants	1 Participants	3 Participants

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Lottery + Monthly Weight n=4 participants at risk Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Lottery + Monthly Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Lottery + Overall Weight + Exercise n=5 participants at risk Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Overall Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Lottery + Overall Weight n=5 participants at risk Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings ($0, $2, $15 or not eligible for lottery due to lack of weighing). Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Lottery + Overall Weight: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Lottery + Monthly Weight + Exercise n=5 participants at risk Participants will be eligible for a daily lottery if they have weighed themselves in the previous day on the e-scale. For each day of the study, participants will be informed of the study's randomly-generated winning lottery number and their winnings if any. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Lottery + Monthly Weight + Exercise: Lottery for daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Monthly Weight n=5 participants at risk Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, participants will be specifically notified that they would have received $14 had they had gained within the recommended range for the month, drawing on research showing that loss aversion can be motivating. Loss + Monthly Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis.	Loss + Overall Weight + Exercise n=5 participants at risk Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the IOM GWG recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Overall Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.	Loss + Overall Weight n=5 participants at risk Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will be given the Institute of Medicine gestational weight gain recommendation based on their body mass index at randomization, adjusted for data collection at 36 weeks. If they achieve the goal at 36 weeks, they will receive $112 after the data collection visit. Loss + Overall Weight: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) by the end of the study.	Loss + Monthly Weight + Exercise n=5 participants at risk Participants randomized to an arm that contains the self-weighing (certain loss) component will have a balance of $3.50 at the beginning of each week of the study and each day that they do not weigh, $0.50 will be subtracted from this account. Participants will receive $14 per month if they have gained within the recommended monthly range for their BMI category. Otherwise, they will be notified that they would have received $14 had they had gained within the recommendation for the month. Participants will be asked to engage in 150 minutes of exercise each week based on the guideline from the ACOG. They will receive $3.50 if they meet their activity goal for the week. Otherwise, they will be notified that they would have received $3.50 had they meet their activity goal. Loss + Monthly Weight + Exercise: Certain loss for not engaging in daily self-weighing. Incentives for gaining weight within a recommended (by Institute of Medicine) on a monthly basis. Incentives for meeting an exercise goal of 150 minutes of moderate physical activity per week, as recommended by the American College of Obstetricians and Gynecologists.
Pregnancy, puerperium and perinatal conditions Premature birth	0.00% 0/4 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	20.0% 1/5 • Number of events 1 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	20.0% 1/5 • Number of events 1 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim
Pregnancy, puerperium and perinatal conditions Miscarriage	25.0% 1/4 • Number of events 1 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim	0.00% 0/5 • Baseline to 36 weeks gestation Data on adverse events, consistent with the clinicaltrials.gov definition, were collected at data collection visits and as reported by participants in the interim

Other adverse events

Adverse event data not reported

Additional Information

Dr. Rebecca Krukowski

University of Virginia, School of Medicine

Phone: 9014482426

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place