Transcutaneous Electrical Nerve Stimulation (TENS) for IUD Insertion Pain

The researchers will recruit eligible participants from patients who opt for IUD initiation during ambulatory care visits to the Mount Sinai Complex Family Planning service at Mount Sinai Hospital, Mount Sinai Beth Israel, Mount Sinai Morningside, and Mount Sinai West. Allocation to treatment will be based on a 1:1 blocked randomization scheme stratified by parity. A member of the research/clinical team other than the person performing IUD insertion will identify the treatment allocation assigned to the corresponding subject ID. The team member will set up the TENS unit accordingly by applying pads to the participant and initiating treatment with the correct settings. When setup is complete (\<5 minutes), the person performing the IUD insertion and other clinical staff assisting with the procedure will enter the exam room with no knowledge of TENS treatment assignment to insert the IUD. REDCap, a HIPAA-compliant, secure web application used for building and managing online surveys and databases, will be used for data collection in this study. Participants will complete electronic surveys in REDCap during the study. The first survey is a baseline survey to collect demographics as well as medical, obstetric, and gynecologic history and other characteristics prior to the IUD insertion procedure. IUD insertion will be performed by complex family planning faculty and fellows, as well as OB/GYN residents on their family planning rotation. A research staff member will be within reach of the study participant during the procedure to collect pain scores using a visual analog scale (VAS) presented on an iPad. The second survey will have a visual analog scale for study participants to rate their pain between 0 and 100 at the following timepoints during IUD insertion: 1. Baseline 2. Immediately after bimanual exam 3. Immediately after speculum insertion 4. Immediately after tenaculum placement 5. Immediately after uterine sounding 6. Immediately after IUD insertion 7. 5 minutes after speculum removal The third survey will ask participants about reflections on their experience with IUD insertion and acceptability of the TENS device. Participation in the study is expected to only last one day, the day of IUD insertion.