A randomized controlled trial of laminaria, oral misoprostol, and vaginal misoprostol before abortion*1

Abstract
Objective: To compare the efficacy and acceptability of oral misoprostol, vaginal misoprostol, and laminaria tents for cervical dilation before surgical abortion. Methods: We conducted a randomized, double-blind, placebo-controlled trial comparing oral misoprostol 400 μg, vaginal misoprostol 400 μg, and one medium laminaria for dilating the cervix over 4 hours before surgical abortion. The study sample consisted of 106 women at 7–14 weeks’ gestation who presented to San Francisco General Hospital requesting abortion. The primary outcome was the amount of cervical dilation measured by Pratt dilators. Secondary outcomes were the proportion of subjects needing further manual dilation, difficulty of dilation, duration of the procedure, blood loss, and side effects. Results: The vaginal-misoprostol group had a significantly greater mean dilation (28.0 mm) than the oral misoprostol group (24.2 mm; P < .05) and a greater mean dilation than the laminaria group (25.9 mm), although this difference did not reach significance. Women who received laminaria reported significantly more pain at the time of placement (85.7% reported at least “a little” pain) compared with women who received misoprostol by either route (28.9% of oral-misoprostol and 34.0% of vaginal-misoprostol subjects reported “a little” pain; P < .01). The proportion of subjects who required further manual dilation, ease of dilation, duration of the procedure, and blood loss were not significantly different among the groups. There was no difference in side effects during the 4-hour waiting period among the three groups, and gastrointestinal side effects were rare in all groups. Conclusion: Vaginal misoprostol is superior to oral misoprostol and is an acceptable alternative to laminaria tents for cervical dilation before surgical abortion in pregnancies of 7–14 weeks’ gestation. It is inexpensive and easy to administer, and achieves equal or greater dilation with less pain on insertion and no increase in side effects compared with laminaria.