Null findings from similar study.

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 or replacement during ambulatory care visits at the Center for Women's Health and Midwifery and Yale Family Planning Clinic. Allocation to treatment will be based on a 1:1 blocked randomization scheme. A member of the research/clinical staff other than the provider performing IUD insertion will identify the treatment allocation assigned to the corresponding subject ID. The research staff 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, the provider 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 three 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. If applicable, immediately after IUD removal
5. Immediately after tenaculum placement
6. Immediately after uterine sounding
7. Immediately after IUD insertion
8. 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, and their past experiences. Clinical Providers who perform the IUD insertion will be asked to take a post IUD insertion survey. This survey will ask questions about the insertion and perceived patient pain.

Participation in the study is expected to only last one day, the day of IUD insertion.

Inclusion Criteria Patient Participants:

• Provision of signed and dated informed consent form.
• Stated willingness to comply with all study procedures and availability for the duration of the study.
• English-speaking individual aged 18 years or older.
• Presenting for IUD initiation or replacement during ambulatory care visits to the Yale Family Planning service and Center for Women's Health and Midwifery clinic.
• Opting for either LNG 52mg or copper T380A IUD.

Inclusion Criteria Provider Participants:

• Review of the provider participant study Information Sheet and provision of verbal consent.
• IUD insertion performed by Yale Family Planning and Center for Women's Health and Midwifery clinic faculty and fellows, as well as OB/GYN residents on their family planning rotation, with IUD insertion competency.
• Performing an IUD insertion on a patient participant who meets all patient participant eligibility criteria

Exclusion Criteria Patient Participants:

• Contraindication to IUD initiation
• Current Pelvic Infection
• Distorted Uterine Anatomy (I.e., uterine septum, didelphys, uterine fibroids with cavity length greater than 12mm)
• Pregnancy
• Any other contraindications to IUD insertion as determined by the patient's clinical care staff.
• Exclusionary criteria for study participation
• Current IUD with no visible strings
• Contraindication or allergy to ibuprofen
• History of chronic pain disorder
• Recent opioid use in the previous 30 days
• History of 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)
• History of epilepsy
• BMI > 50
• History of TENS use
• Planned pain intervention outside standard of care OR pre-procedure use of non-standard pain medication

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.