The effects of vasopressin injection on uterine artery blood flow during dilation and evacuation

Objective: This study was undertaken to determine whether vasopressin decreases uterine artery blood flow and blood loss in early second-trimester surgical abortions (dilation and evacuation). Study Design: Randomized, double blind, placebo-controlled trial of a saline paracervical block with or without vasopressin before dilation and evacuation. Uterine artery pulsatility index and blood loss were measured. Results: Demographics were similar in both groups (mean gestational age 16.8 weeks, SD 1.7). Of 35 randomly assigned patients, Doppler waveforms were adequate in 28 patients (vasopressin, n = 13; placebo, n = 15). The mean difference in uterine artery pulsatility index before and after injection between groups was not significantly different (P = .14). Procedural blood loss was no different. Conclusion: Paracervical vasopressin compared to placebo injection did not result in significant changes in uterine artery pulsatility index in early second-trimester dilation and evacuation procedures.