Paracervical Block for Saline Infusion Sonogram in Fertility Evaluation: A Randomized Controlled Trial

Pain management options (or lack thereof) during routine gynecologic procedures has become a women's health concern with growing prominence. Patients increasingly are reporting their "excruciating" pain experiences from gynecologic procedures ranging from pap smears to intrauterine device placements. When pain during gynecologic procedures is not well managed, gynecologic care quality and frequency suffers - one study found that in a group of middle-aged black women, those who perceived pap smears to be painful were almost five times more likely to not adhere to regular pap screening recommendations. Women, similarly, may avoid other elective gynecologic procedures, such as intrauterine device placement or saline infusion sonograms, out of fear of pain during the procedure.

Recent evidence has found that local anesthesia can significantly reduce pain during certain procedures, such as surgical abortion and intrauterine device placement (IUD). For example, in two randomized controlled trials of nulliparous women undergoing intrauterine device placement, a 10-20cc buffered 1% lidocaine paracervical block decreased pain during and following IUD placement. However, this reduction in pain may not be significant in multiparous women-in systematic review and meta-analysis of randomized clinical trials (RCTs) of pain management options for women undergoing IUD placement, paracervical blocks were not found to reduce pain in a statistically significant fashion. In women undergoing surgical abortion, a 20cc 1% lidocaine injection significantly reduced pain during dilation and aspiration regardless of parity status.

In reproductive endocrinology and infertility offices, saline infusion sonogram is often performed in the evaluation of uterine cavity and patency of the fallopian tubes. This is a procedure that is demonstrated to cause mild to moderate pain in most patients. These procedures do not standardly receive any local anesthesia, though many practices will recommend an over-the-counter nonsteroidal anti-inflammatory drug (NSAID) prior to procedure. Although no previous study has been published on NSAIDs specifically, a prospective observational study did find that pre-medication of paracetamol + codeine prior to saline ultrasound assessment of uterine cavity and tubal patency significantly reduced pain.

While local anesthesia is not routinely offered during these saline infusion sonograms, several studies have investigated its potential effect. One randomized controlled trial assessed the pain relief effect of topical and intrauterine lidocaine during saline ultrasound, and found no difference in pain compared to placebo. Of note, these saline ultrasounds were only for cavity evaluation, not tubal evaluation, and therefore did not utilize a balloon catheter. Another randomized controlled trial of 96 Turkish women found that paracervical block significantly reduced pain during saline infusion sonogram compared to the placebo group. However, of note, this protocol utilized a tenaculum, which is not routinely used in saline infusion sonograms in the United States for fertility evaluation. Additionally, the catheter diameter used was wider than is used in the clinic (4mm versus 1.67mm). This study also did not appear to evaluate for tubal patency, as the catheter described was not a balloon catheter.

In this study, the investigators aim to add to the existing literature on pain management during saline infusion sonograms to determine if lidocaine paracervical blocks decrease perceived pain in saline ultrasounds that assess for uterine cavity and tubal patency. This will be accomplished by determining if paracervical block provides clinically significant pain relief compared to no anesthesia during saline ultrasound evaluation of uterine cavity and tubal patency.