The effect of nitroglycerin on the IUD insertion experience in nulliparous women: a pilot study

Concern about pain during placement of an intrauterine device (IUD) represents a barrier to use, especially among nulliparous women. We hypothesized that nitroglycerin gel applied vaginally 30 min prior to IUD placement would reduce insertion-related pain.

We designed a randomized, double-blinded, placebo-controlled pilot study to evaluate the efficacy and tolerability of 0.5-mg nitroglycerin gel (1 mL) or identical placebo gel applied vaginally in nulliparous women 30 min prior to IUD placement. The study was limited to women who opted for the levonorgestrel-releasing intrauterine system. Subjects completed a series of 100-mm visual analogue scales at several time points. The primary outcome was subject-reported pain with passage of the IUD through the cervix. Secondary outcomes included subject-reported pain at other time points, provider-reported ease of insertion, side effects, adverse events and need for additional dilation.

A total of 24 women were randomized. Baseline characteristics were similar between groups. The mean pain score with IUD deployment was 55.0 mm [standard deviation (SD) = 29.7 mm] in the placebo group and 57.4 mm (SD 22.1 mm) in the nitroglycerin group (p=.82). There was no difference in ease of insertion reported by providers. Two subjects required dilation, one in each group.

Vaginal administration of 0.5-mg nitroglycerin gel 30 min prior to IUD placement does not appear to decrease patient-reported procedural pain among nulliparous women or ease of insertion for providers.