The Impact of Pain Scores on Intrauterine Lidocaine Versus Normal Saline Infusion at the Time of IUD Placement

IUDs are the most frequently used method of reversible birth control. The placement procedure is straightforward, but can cause the women cramping and pain. Every woman is advised to take Ibuprofen or acetaminophen prior to her appointment. Gentle techniques and distraction are used to minimize discomfort. However, some women still have measurable pain during and immediately after the procedure.

Investigators have shown that infusion of 5cc of a 2% concentration of liquid lidocaine into the inside of the uterus can reduce the pain that is associated with other procedures, such as biopsies done of the lining of the uterus. The investigators seek to determine if a similar infusion made before IUD placement may reduce pain. Because pain is a subjective complaint and because plastic tubing is being used to sound the uterus instead of the usual metal probe (a uterine sound), the investigators have included a placebo arm with saline infusion. All women will receive oral medication in advance of IUD placement, so no woman will be subject to placebo only.

Those women undergoing routine screening for IUD candidacy will be approached. Medical and social history and routine laboratory testing are to be done. The risks, benefits, and side effects of IUD placement will be explained. They will sign consent forms for the IUD from both the manufacturer and the clinic before evaluation for possible inclusion in this study. Informed consent for the study will be obtained either at that visit or on the day of the IUD placement. All the routine IUD placement steps will be done and she will rate the pain score. A standardized pain scale from 1-10, with 10 being the worst pain in the patient's lifetime, will be used here and at every point in the study. Depth of the uterus will be determined by introducing a plastic tubing into the woman's uterus. This tubing will either be filled with 1.3cc of normal saline or 2% lidocaine. The liquid will be infused at certain points within the cervix and uterus. She will again be asked to rate her pain score for that procedure. The tubing will be removed and the IUD will be placed. After the IUD is in the correct position, but before removal of the tenaculum, she will again be asked to rate her pain score for that procedure. After the IUD placement procedure is complete and the patient is dressed, she will be asked to assign an overall pain score. Pain scores between placebo and study drug used will be compared (mean, median and range). Fisher T tests will be performed to determine statistical significance with the p< 0.05 as a cutoff. Sub-analysis will be done comparing scores of which women who have never been pregnant to those who have. If possible, comparisons of pain scores will be made for women who have had vaginal deliveries compared to those who delivered by C-section. The risks to the patient for this study intervention are minimal.

Inclusion criteria

• Women eligible for IUD insertion
• Willing to give consent

Exclusion criteria

• Allergy to lidocaine
• Contraindications to IUD use