Trial Outcomes & Findings for Study on Medical Records of Women Using an Intrauterine Device (IUD) to Analyze the Risks That the IUD Will be Expelled or Perforates the Womb in Relation to Breastfeeding, the Point in Time When the IUD Was Inserted After Childbirth and in Relation to Different Types of IUDs (NCT NCT03754556)
NCT ID: NCT03754556
Last Updated: 2020-12-04
Results Overview
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
COMPLETED
326658 participants
Up to 11 years
2020-12-04
Participant Flow
This study was a retrospective cohort study, using the data from three health care systems: Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and one research institute with access to a health information exchange, Regenstrief Institute (RI)
Between 01 January 2001 and 30 April 2018, 326658 participants were identified: 322898 participants with intrauterine device (IUD) type available and 94817 participants with breastfeeding status available (and IUD insertion within 12 months postpartum)
Participant milestones
| Measure |
Women With IUD
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Overall Study
STARTED
|
326658
|
|
Overall Study
COMPLETED
|
326658
|
|
Overall Study
NOT COMPLETED
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Study on Medical Records of Women Using an Intrauterine Device (IUD) to Analyze the Risks That the IUD Will be Expelled or Perforates the Womb in Relation to Breastfeeding, the Point in Time When the IUD Was Inserted After Childbirth and in Relation to Different Types of IUDs
Baseline characteristics by cohort
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
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Age, Customized
≤ 28 years
|
119469 Participants
n=5 Participants
|
|
Age, Customized
> 28 to ≤ 36 years
|
107871 Participants
n=5 Participants
|
|
Age, Customized
> 36 to ≤ 50 years
|
99318 Participants
n=5 Participants
|
|
Sex/Gender, Customized
Female
|
326658 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Asian/Pacific Islander
|
38911 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Hispanic black
|
696 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Hispanic white
|
42501 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Hispanic other
|
56180 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Non-Hispanic black
|
28323 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Non-Hispanic white
|
137102 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Other or multiple
|
16357 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Unknown
|
6588 Participants
n=5 Participants
|
|
Breastfeeding status
Yes (for those ≤ 52 weeks postpartum)
|
64186 Participants
n=5 Participants
|
|
Breastfeeding status
No (for those ≤ 52 weeks postpartum)
|
30631 Participants
n=5 Participants
|
|
Breastfeeding status
Undetermined (for those ≤ 52 weeks postpartum)
|
3007 Participants
n=5 Participants
|
|
Breastfeeding status
No delivery in the past year
|
228834 Participants
n=5 Participants
|
|
Postpartum time of IUD insertion
0 to 3 days
|
2788 Participants
n=5 Participants
|
|
Postpartum time of IUD insertion
4 days to ≤ 6 weeks
|
17272 Participants
n=5 Participants
|
|
Postpartum time of IUD insertion
> 6 to ≤ 14 weeks
|
56047 Participants
n=5 Participants
|
|
Postpartum time of IUD insertion
> 14 to ≤ 52 weeks
|
21717 Participants
n=5 Participants
|
|
Postpartum time of IUD insertion
> 52 weeks or no delivery
|
228834 Participants
n=5 Participants
|
|
Menorrhagia
≤ 12 months before insertion
|
32552 Participants
n=5 Participants
|
|
Menorrhagia
> 12 months or no diagnosis
|
294106 Participants
n=5 Participants
|
|
IUD type
Levonorgestrel (LNG)-IUD
|
259234 Participants
n=5 Participants
|
|
IUD type
Copper IUD
|
63664 Participants
n=5 Participants
|
|
IUD type
Unknown
|
3760 Participants
n=5 Participants
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding
|
4.25 per 1000 person-years
Interval 3.89 to 4.62
|
|
Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding
|
2.50 per 1000 person-years
Interval 2.11 to 2.94
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
0.60 number of outcomes/IUD insertions (%)
Interval 0.54 to 0.67
|
|
Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
0.35 number of outcomes/IUD insertions (%)
Interval 0.29 to 0.43
|
|
Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
1.61 number of outcomes/IUD insertions (%)
Interval 1.43 to 1.81
|
|
Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
0.88 number of outcomes/IUD insertions (%)
Interval 0.71 to 1.08
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women who had given birth in the previous 52 weeks and had breastfeeding status "yes" or "no" were included in this analysis
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of uterine perforation among women who were not breastfeeding at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
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|---|---|
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Adjusted Hazard Ratio (HR) for Breastfeeding Status and Uterine Perforation-first Observed IUD Insertions
|
1.37 ajusted hazard ratio
Interval 1.12 to 1.66
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
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Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks postpartum
|
5.14 per 1000 person-years
Interval 4.44 to 5.92
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|
Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks postpartum
|
3.77 per 1000 person-years
Interval 3.42 to 4.15
|
|
Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks postpartum
|
2.24 per 1000 person-years
Interval 1.8 to 2.75
|
|
Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks postpartum or no delivery
|
0.68 per 1000 person-years
Interval 0.61 to 0.76
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
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Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks postpartum (pp), 1 year of follow-up
|
0.70 number of outcomes/IUD insertions (%)
Interval 0.59 to 0.84
|
|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks pp, 1 year of follow-up
|
0.54 number of outcomes/IUD insertions (%)
Interval 0.48 to 0.61
|
|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks pp, 1 year of follow-up
|
0.33 number of outcomes/IUD insertions (%)
Interval 0.26 to 0.43
|
|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks pp or no delivery, 1 year of follow-up
|
0.07 number of outcomes/IUD insertions (%)
Interval 0.06 to 0.08
|
|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks pp, 5 years of follow-up
|
1.89 number of outcomes/IUD insertions (%)
Interval 1.55 to 2.31
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|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks pp, 5 years of follow-up
|
1.42 number of outcomes/IUD insertions (%)
Interval 1.25 to 1.61
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|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks pp, 5 years of follow-up
|
0.74 number of outcomes/IUD insertions (%)
Interval 0.57 to 0.97
|
|
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks pp or no delivery, 5 years of follow-up
|
0.29 number of outcomes/IUD insertions (%)
Interval 0.26 to 0.34
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity scores and breastfeeding status, to evaluate whether the risk of uterine perforation among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of uterine perforation among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks. Reference group: IUD insertion \> 52 weeks postpartum
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions
≤ 6 weeks postpartum
|
6.29 ajusted hazard ratio
Interval 4.5 to 8.79
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks postpartum
|
4.65 ajusted hazard ratio
Interval 3.49 to 6.2
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks postpartum
|
2.94 ajusted hazard ratio
Interval 2.16 to 4.01
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
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|---|---|
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Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and Uterine Perforation-first Observed IUD Insertions
|
3.44 adjusted hazard ratio
Interval 2.7 to 4.4
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PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
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Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and Uterine Perforation-first Observed IUD Insertions
|
4.36 adjusted hazard ratio
Interval 3.45 to 5.51
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity score, overall and stratified by breastfeeding status at the time of IUD insertion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up. Reference group: \> 36 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Overall, 1 year of follow-up
|
4.72 adjusted incidence rate ratio
Interval 3.74 to 5.96
|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Overall, 5 years of follow-up
|
4.10 adjusted incidence rate ratio
Interval 3.43 to 4.9
|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
1.11 adjusted incidence rate ratio
Interval 0.57 to 2.47
|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
6.61 adjusted incidence rate ratio
Interval 5.03 to 8.76
|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
1.47 adjusted incidence rate ratio
Interval 0.8 to 3.07
|
|
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
4.86 adjusted incidence rate ratio
Interval 4.0 to 5.93
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Propensity score-adjusted incidence rate differences (per 1,000 person-years) for uterine perforation for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status. Reference group: \> 36 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Overall, 1 year of follow-up
|
3.75 per 1000 person-years
Interval 3.05 to 4.45
|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Overall, 5 years of follow-up
|
2.28 per 1000 person-years
Interval 1.93 to 2.63
|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
0.63 per 1000 person-years
Interval -3.39 to 4.64
|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
3.92 per 1000 person-years
Interval 3.22 to 4.63
|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
1.38 per 1000 person-years
Interval -0.46 to 3.21
|
|
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
2.33 per 1000 person-years
Interval 1.97 to 2.69
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD
|
1.64 per 1000 person-years
Interval 1.53 to 1.76
|
|
Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
Copper IUD
|
1.27 per 1000 person-years
Interval 1.08 to 1.48
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD, 1 year of follow up
|
0.22 number of outcomes/IUD insertions (%)
Interval 0.2 to 0.24
|
|
Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
Copper IUD, 1 year of follow up
|
0.16 number of outcomes/IUD insertions (%)
Interval 0.13 to 0.2
|
|
Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD, 5 years of follow up
|
0.63 number of outcomes/IUD insertions (%)
Interval 0.57 to 0.68
|
|
Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
Copper IUD, 5 years of follow up
|
0.55 number of outcomes/IUD insertions (%)
Interval 0.44 to 0.68
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of uterine perforation among women with copper IUD at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for IUD Type and Uterine Perforation-first Observed IUD Insertions
|
1.49 adjusted hazard ratio
Interval 1.25 to 1.78
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes
|
1.00 per 1000 person-years
Interval 0.77 to 1.28
|
|
Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
No
|
1.63 per 1000 person-years
Interval 1.53 to 1.74
|
PRIMARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes, 1 year of follow-up
|
0.10 number of outcomes/IUD insertions (%)
Interval 0.07 to 0.14
|
|
Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
No, 1 year of follow-up
|
0.22 number of outcomes/IUD insertions (%)
Interval 0.2 to 0.24
|
|
Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes, 5 years of follow-up
|
0.41 number of outcomes/IUD insertions (%)
Interval 0.31 to 0.56
|
|
Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
No, 5 years of follow-up
|
0.63 number of outcomes/IUD insertions (%)
Interval 0.58 to 0.69
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of uterine perforation among women who do not have this indication
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Menorrhagia Status and Uterine Perforation-first Observed IUD Insertions
|
1.38 adjusted hazard ratio
Interval 1.01 to 1.88
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women who had given birth in the previous 52 weeks and had breastfeeding status "yes" or "no" were included in this analysis
Propensity score-adjusted hazard ratios to evaluate the extent to which breastfeeding status (yes vs. no) modified the association of uterine perforation for women with IUD insertion at different time periods postpartum (i.e., IUD insertion ≤ 14 weeks versus IUD insertion \> 14 weeks postpartum) among women with a recorded delivery within the past 52 weeks at the time of the first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation
≤ 14 weeks, breastfeeding yes vs.no
|
1.28 adjusted hazard ratio
Interval 1.02 to 1.61
|
|
Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation
> 14 to ≤ 52 weeks, breastfeeding yes vs.no
|
2.41 adjusted hazard ratio
Interval 1.47 to 3.95
|
|
Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation
Breastfeeding yes, ≤ 14 vs. > 14 to ≤ 52 weeks
|
1.36 adjusted hazard ratio
Interval 1.01 to 1.83
|
|
Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation
Breastfeeding no, ≤ 14 vs. > 14 to ≤ 52 weeks
|
2.56 adjusted hazard ratio
Interval 1.62 to 4.02
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women who had given birth in the previous 52 weeks and had breastfeeding status "yes" or "no" were included in this analysis
Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=94205 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation
LNG-IUD, breastfeeding yes vs.no
|
1.33 adjusted hazard ratio
Interval 1.07 to 1.64
|
|
Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation
Copper IUD, breastfeeding yes vs.no
|
1.66 adjusted hazard ratio
Interval 0.94 to 2.94
|
PRIMARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
LNG-IUD, ≤ 6 weeks
|
6.78 adjusted hazard ratio
Interval 4.74 to 9.7
|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
LNG-IUD, > 6 to ≤ 14 weeks
|
5.11 adjusted hazard ratio
Interval 3.75 to 6.95
|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
LNG-IUD, > 14 to ≤ 52 weeks
|
3.13 adjusted hazard ratio
Interval 2.21 to 4.42
|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
Copper IUD, ≤ 6 weeks
|
4.30 adjusted hazard ratio
Interval 2.38 to 7.75
|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
Copper IUD, > 6 to ≤ 14 weeks
|
2.61 adjusted hazard ratio
Interval 1.56 to 4.36
|
|
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
Copper IUD, > 14 to ≤ 52 weeks
|
2.01 adjusted hazard ratio
Interval 1.05 to 3.85
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding
|
10.23 per 1000 person-years
Interval 9.68 to 10.81
|
|
Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding
|
14.58 per 1000 person-years
Interval 13.62 to 15.59
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
1.55 number of outcomes/IUD insertions (%)
Interval 1.44 to 1.65
|
|
Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
2.45 number of outcomes/IUD insertions (%)
Interval 2.27 to 2.65
|
|
Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
3.49 number of outcomes/IUD insertions (%)
Interval 3.25 to 3.73
|
|
Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
4.57 number of outcomes/IUD insertions (%)
Interval 4.22 to 4.95
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women who had given birth in the previous 52 weeks and had breastfeeding status "yes" or "no" were included in this analysis
Propensity score-adjusted to evaluate whether the risk of IUD expulsion among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of IUD expulsion among women who were not breastfeeding at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=94817 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Breastfeeding Status and IUD Expulsion-first Observed IUD Insertions
|
0.71 adjusted hazard ratio
Interval 0.64 to 0.78
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 3 days
|
46.54 per 1000 person-years
Interval 40.54 to 53.18
|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
4 days to ≤ 6 weeks
|
10.88 per 1000 person-years
Interval 9.78 to 12.08
|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks postpartum
|
15.33 per 1000 person-years
Interval 14.1 to 16.65
|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks postpartum
|
9.29 per 1000 person-years
Interval 8.73 to 9.87
|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks postpartum
|
14.36 per 1000 person-years
Interval 13.22 to 15.57
|
|
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks postpartum or no delivery
|
14.93 per 1000 person-years
Interval 14.57 to 15.29
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks pp or no delivery, 5 years of follow-up
|
4.88 number of outcomes/IUD insertions (%)
Interval 4.74 to 5.02
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 3 days, 1 year of follow-up
|
7.84 number of outcomes/IUD insertions (%)
Interval 6.83 to 9.0
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
4 days to ≤ 6 weeks, 5 years of follow-up
|
3.87 number of outcomes/IUD insertions (%)
Interval 3.4 to 4.42
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks postpartum (pp), 1 year of follow-up
|
2.46 number of outcomes/IUD insertions (%)
Interval 2.24 to 2.71
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks pp, 1 year of follow-up
|
1.40 number of outcomes/IUD insertions (%)
Interval 1.3 to 1.51
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks pp, 1 year of follow-up
|
2.33 number of outcomes/IUD insertions (%)
Interval 2.12 to 2.56
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 52 weeks pp or no delivery, 1 year of follow-up
|
2.49 number of outcomes/IUD insertions (%)
Interval 2.42 to 2.56
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 3 days, 5 years of follow-up
|
10.73 number of outcomes/IUD insertions (%)
Interval 9.12 to 12.61
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
4 days to ≤ 6 weeks, 1 year of follow-up
|
1.61 number of outcomes/IUD insertions (%)
Interval 1.42 to 1.84
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
≤ 6 weeks pp, 5 years of follow-up
|
4.81 number of outcomes/IUD insertions (%)
Interval 4.33 to 5.33
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks pp, 5 years of follow-up
|
3.18 number of outcomes/IUD insertions (%)
Interval 2.95 to 3.42
|
|
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks pp, 5 years of follow-up
|
4.55 number of outcomes/IUD insertions (%)
Interval 4.12 to 5.02
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity score and breastfeeding status, to evaluate whether the risk of IUD expulsion before and after 49 days of insertion among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of IUD expulsion among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks Reference group: IUD insertion \> 52 weeks postpartum
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
Within 49 days, ≤ 6 weeks postpartum (pp)
|
1.93 adjusted hazard ratio
Interval 1.59 to 2.35
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
Within 49 days, > 6 weeks and ≤ 14 weeks pp
|
0.88 adjusted hazard ratio
Interval 0.74 to 1.05
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
Within 49 days, > 14 weeks and ≤ 52 weeks pp
|
1.38 adjusted hazard ratio
Interval 1.14 to 1.68
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
After 49 days, ≤ 6 weeks pp
|
1.32 adjusted hazard ratio
Interval 1.15 to 1.53
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
After 49 days, > 6 weeks and ≤ 14 weeks pp
|
1.03 adjusted hazard ratio
Interval 0.92 to 1.16
|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
After 49 days, > 14 weeks and ≤ 52 weeks pp
|
1.39 adjusted hazard ratio
Interval 1.23 to 1.57
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and IUD Expulsion-first Observed IUD Insertions
|
0.88 adjusted hazard ratio
Interval 0.83 to 0.94
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and IUD Expulsion-first Observed IUD Insertions
|
0.95 adjusted hazard ratio
Interval 0.89 to 1.0
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Overall and stratified by breastfeeding status at the time of IUD insertion for IUD expulsion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up Reference group: \> 36 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Overall, 1 year of follow-up
|
1.21 adjusted incidence rate ratio
Interval 1.12 to 1.3
|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Overall, 5 years of follow-up
|
1.20 adjusted incidence rate ratio
Interval 1.13 to 1.28
|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
0.60 adjusted incidence rate ratio
Interval 0.44 to 0.85
|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
1.25 adjusted incidence rate ratio
Interval 1.16 to 1.35
|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
0.80 adjusted incidence rate ratio
Interval 0.59 to 1.1
|
|
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
1.23 adjusted incidence rate ratio
Interval 1.15 to 1.31
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
Adjusted incidence rate differences (per 1,000 person-years) for IUD expulsion for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status Reference group: \> 36 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Overall, 1 year of follow-up
|
4.28 per 1000 person-years
Interval 2.5 to 6.06
|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Overall, 5 years of follow-up
|
2.37 per 1000 person-years
Interval 1.53 to 3.22
|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Breastfeeding, 1 year of follow-up
|
-10.79 per 1000 person-years
Interval -19.43 to -2.15
|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Breastfeeding, 5 years of follow-up
|
-2.62 per 1000 person-years
Interval -6.51 to 1.26
|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Not breastfeeding, 1 year of follow-up
|
5.11 per 1000 person-years
Interval 3.27 to 6.94
|
|
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Not breastfeeding, 5 years of follow-up
|
2.65 per 1000 person-years
Interval 1.78 to 3.53
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD
|
13.95 per 1000 person-years
Interval 13.63 to 14.28
|
|
Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
Copper IUD
|
14.08 per 1000 person-years
Interval 13.44 to 14.75
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD, 1 year of follow up
|
2.30 number of outcomes/IUD insertions (%)
Interval 2.24 to 2.36
|
|
Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
Copper IUD, 1 year of follow up
|
2.30 number of outcomes/IUD insertions (%)
Interval 2.18 to 2.44
|
|
Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
LNG-IUD, 5 years of follow up
|
4.52 number of outcomes/IUD insertions (%)
Interval 4.4 to 4.65
|
|
Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
Copper IUD, 5 years of follow up
|
4.82 number of outcomes/IUD insertions (%)
Interval 4.56 to 5.1
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Propensity score adjusted to evaluate whether the risk of IUD expulsion among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of IUD expulsion among women with copper IUD at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for IUD Type and IUD Expulsion-first Observed IUD Insertions
|
0.69 adjusted hazard ratio
Interval 0.65 to 0.73
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes
|
39.56 per 1000 person-years
Interval 38.03 to 41.13
|
|
Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
No
|
11.10 per 1000 person-years
Interval 10.83 to 11.38
|
SECONDARY outcome
Timeframe: At 1 year and 5 years of follow-upPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
No, 1 year of follow-up
|
1.78 number of outcomes/IUD insertions (%)
Interval 1.73 to 1.84
|
|
Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes, 1 year of follow-up
|
6.89 number of outcomes/IUD insertions (%)
Interval 6.6 to 7.2
|
|
Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
Yes, 5 years of follow-up
|
11.89 number of outcomes/IUD insertions (%)
Interval 11.4 to 12.41
|
|
Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
No, 5 years of follow-up
|
3.72 number of outcomes/IUD insertions (%)
Interval 3.61 to 3.83
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
Propensity score adjusted to evaluate whether the risk of IUD expulsion among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of IUD expulsion among women who do not have this indication
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Adjusted Hazard Ratio (HR) for Menorrhagia Status and IUD Expulsion-first Observed IUD Insertions
|
2.79 adjusted hazard ratio
Interval 2.62 to 2.98
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women who had given birth in the previous 52 weeks and had breastfeeding status "yes" or "no" were included in this analysis
Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion
Outcome measures
| Measure |
Women With IUD
n=94205 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion
LNG-IUD, breastfeeding yes vs.no
|
0.72 adjusted hazard ratio
Interval 0.64 to 0.8
|
|
Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion
Copper IUD, breastfeeding yes vs.no
|
0.66 adjusted hazard ratio
Interval 0.54 to 0.8
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery
Outcome measures
| Measure |
Women With IUD
n=322898 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
LNG-IUD, ≤ 6 weeks
|
1.59 adjusted hazard ratio
Interval 1.38 to 1.82
|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
LNG-IUD, > 6 to ≤ 14 weeks
|
1.01 adjusted hazard ratio
Interval 0.9 to 1.14
|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
LNG-IUD, > 14 to ≤ 52 weeks
|
1.40 adjusted hazard ratio
Interval 1.23 to 1.58
|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
Copper IUD, ≤ 6 weeks
|
1.23 adjusted hazard ratio
Interval 0.98 to 1.53
|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
Copper IUD, > 6 to ≤ 14 weeks
|
0.96 adjusted hazard ratio
Interval 0.81 to 1.13
|
|
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
Copper IUD, > 14 to ≤ 52 weeks
|
1.35 adjusted hazard ratio
Interval 1.13 to 1.63
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions
To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
Overall
|
29777 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
Breastfeeding
|
1686 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
Not breastfeeding
|
1077 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
≤ 6 weeks postpartum
|
573 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
> 6 weeks and ≤ 14 weeks postpartum
|
1261 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
> 14 weeks and ≤ 52 weeks postpartum
|
1146 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
> 52 weeks postpartum or no delivery
|
26797 indicators
|
SECONDARY outcome
Timeframe: Up to 11 yearsPopulation: Women with first observed IUD insertions
To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users)
Outcome measures
| Measure |
Women With IUD
n=326658 Participants
Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases.
|
|---|---|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
Overall
|
29777 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
LNG-IUD
|
24666 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
Copper IUD
|
4648 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
With menorrhagia in the past year
|
3754 indicators
|
|
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
Without menorrhagia in the past year
|
26023 indicators
|
Adverse Events
Women With IUD
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee PI shall ensure that a written manuscript of any intended publication will be provided to BAYER at least 30 days prior to the intended submission or presentation in order to allow BAYER to review it. PI further agrees, upon written request from BAYER, not to submit such abstract or manuscript for publication or to make such presentation for the reasonably required time in order to allow for actions to be taken, which are necessary for BAYER to preserve rights to patents.
- Publication restrictions are in place
Restriction type: OTHER