This study is a double-blind, randomized, placebo-controlled trial to evaluate the use of high frequency TENS for pain control during IUD insertion. Transcutaneous electrical nerve stimulation (TENS) is a relatively low-cost, low-risk, non-pharmacologic intervention for pain management. Previous studies have found that TENS reduces pain associated with other outpatient gynecological procedures. Participants will be randomized in a 1:1 ratio to either active treatment or placebo (placebo TENS) and record pain scores using a 100 mm visual analog scale (VAS) at the time of IUD insertion. The same device will be used for both active and placebo treatment.

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.

Inclusion Criteria:

In order to participate in the study, an individual must meet all the following criteria:

• Presenting for IUD initiation during ambulatory care visits to the Mount Sinai Complex Family Planning service
• Provision of signed and dated informed consent form for IUD Insertion
• English speaking and age 18 or older
• Opting for either LNG 52mg or copper T380A IUD
• Stated willingness to comply with all study procedures

Exclusion Criteria:

• Contraindication to IUD initiation (i.e. pregnancy, current pelvic infection, distorted uterine anatomy)
• Contraindication or allergy to ibuprofen
• History of a chronic pain disorder
• Recent opioid use in the previous 30 days
• History of a cardiac arrhythmia
• History of heart disease (i.e. atrial fibrillation, congestive heart failure)
• Presence of an implantable device with an electrical discharge (i.e. pacemaker)
• BMI > 50 (class IV obesity)
• History of TENS use
• Planned pain intervention outside standard of care (i.e. paracervical block) OR pre-procedure use of non-standard pain medication (i.e. benzodiazepines, muscle relaxers, gabapentin, benadryl)
• History of epilepsy

Individual participant data meta-analysis for this study will not be done. De-identified individual participant data will be analyzed according to the statistical plan mentioned in the study protocol for manuscript preparation and journal publication. Individual participant data will be shared within the study team. Also, IPD will be shared with the IRB according to institutional guidelines.

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