Trial Outcomes & Findings for Transcutaneous Electrical Nerve Stimulation for Pain Control During First-trimester Abortion (NCT NCT05320432)

NCT ID: NCT05320432

Last Updated: 2025-02-25

Results Overview

Pain with manual cervical dilation, assessed by visual analog scale (VAS, 0-100mm; 0 being "no pain" and 100 being "worst pain imaginable")

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 70 participants
• Primary outcome timeframe: Intra-operative, collected during procedure (up to 30 seconds)
• Results posted on: 2025-02-25

Participant Flow

Participant milestones

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Overall Study STARTED	35	35
Overall Study COMPLETED	35	33
Overall Study NOT COMPLETED	0	2

Reasons for withdrawal

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Overall Study Withdrawal by Subject	0	2

Baseline Characteristics

Transcutaneous Electrical Nerve Stimulation for Pain Control During First-trimester Abortion

Baseline characteristics by cohort

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=35 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.	Total n=70 Participants Total of all reporting groups
Age, Continuous	30.6 years STANDARD_DEVIATION 6.5 • n=5 Participants	29.9 years STANDARD_DEVIATION 7.7 • n=7 Participants	30.2 years STANDARD_DEVIATION 7.1 • n=5 Participants
Sex: Female, Male Female	35 Participants n=5 Participants	35 Participants n=7 Participants	70 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Race (NIH/OMB) Asian	9 Participants n=5 Participants	4 Participants n=7 Participants	13 Participants n=5 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
Race (NIH/OMB) Black or African American	2 Participants n=5 Participants	2 Participants n=7 Participants	4 Participants n=5 Participants
Race (NIH/OMB) White	17 Participants n=5 Participants	20 Participants n=7 Participants	37 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	5 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	6 Participants n=5 Participants	3 Participants n=7 Participants	9 Participants n=5 Participants
Region of Enrollment United States	35 Participants n=5 Participants	35 Participants n=7 Participants	70 Participants n=5 Participants
Nulliparous	11 Participants n=5 Participants	14 Participants n=7 Participants	25 Participants n=5 Participants

PRIMARY outcome

Timeframe: Intra-operative, collected during procedure (up to 30 seconds)

Population: Two excluded from sham as did not complete procedure.

Pain with manual cervical dilation, assessed by visual analog scale (VAS, 0-100mm; 0 being "no pain" and 100 being "worst pain imaginable")

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Pain During Cervical Dilation	44 millimeters on VAS Interval 0.0 to 88.0	50 millimeters on VAS Interval 0.0 to 96.0

SECONDARY outcome

Timeframe: Intra-operative, collected during procedure (up to 30 seconds)

Population: Two participants excluded from sham - did not complete procedure

Pain during aspiration assessed by visual analog scale (VAS, 0-100mm; 0 being "no pain" and 100 being "worst pain imaginable")

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Pain During Procedure	44 millimeters on VAS Interval 0.0 to 100.0	56 millimeters on VAS Interval 3.0 to 100.0

SECONDARY outcome

Timeframe: Post-operative, collected following procedure (up to 20 minutes)

Population: Two excluded from sham - did not complete procedure

Patient experience assessed by visual analog scale (VAS, 0-100mm; 0 being "worst experience possible" and 100 being "best experience possible")

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Overall Experience	75 millimeters on VAS Interval 6.0 to 100.0	62 millimeters on VAS Interval 0.0 to 100.0

SECONDARY outcome

Timeframe: up to 20 minutes

Population: Two excluded from sham - did not complete procedure

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Procedure Time	7.3 minutes Standard Deviation 2.9	8.4 minutes Standard Deviation 4.1

SECONDARY outcome

Timeframe: Post-operative, collected after procedure (up to 30 seconds)

Population: Two excluded from sham - did not complete procedure

Provider experience assessed by visual analog scale (VAS, 0-100mm; 0 being "easiest to use" and 100 being "most difficult to use")

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Provider Perceived Ease of Procedure	16 score on a scale Interval 2.0 to 62.0	15 score on a scale Interval 0.0 to 72.0

SECONDARY outcome

Timeframe: up to 1 hour

Population: Two excluded from sham - did not complete procedure

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Time Spent in Recovery	25.4 minutes Standard Deviation 8.8	24.0 minutes Standard Deviation 10.8

SECONDARY outcome

Timeframe: Post-operative, collected after procedure (up to 30 seconds)

Population: Two participants excluded from sham - did not complete procedure

This outcome is to measure the participant's perceived group allocation.

Outcome measures

Measure	Transcutaneous Electrical Nerve Stimulation (TENS) n=35 Participants Prior to the procedure, the patient will have two sets of two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels for TENS administration. For participants randomized to the experimental group, the non-blinded study coordinator will turn on the TENS unit 5 minutes prior to the procedure and monitor stimulating frequency level (80-100 Hz and pulse duration of 400 microseconds; intensity or frequency will be monitored to be administered to a non-painful level). Transcutaneous electrical nerve stimulation (TENS): A low-level electrical current through the skin activates the descending inhibitory systems in the central nervous system.	Sham n=33 Participants For the participants randomized to sham, the same placement of electrodes will occur, but the unit will not be delivering electrical stimulation. Sham: No current applied through pads.
Number of Participants Who Correctly Identified Whether They Received TENS or Sham	32 Participants	21 Participants

Adverse Events

Transcutaneous Electrical Nerve Stimulation (TENS)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Sham

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Principal Investigator

Stanford University

Phone: 650-497-5175

Email: gynresearch@stanford.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place