3-hour pre-treatment with oral or vaginal misoprostol facilitated vacuum aspiration for pregnancy termination

Abstract

OBJECTIVE To compare the efficacy of the vaginal and oral routes of administration of misoprostol, and to determine the optimal dose, for cervical priming prior to vacuum aspiration for first trimester termination of pregnancy in nulliparous women. DESIGN Randomized, double-blind, five-arm, double-placebo-controlled trial. SETTING University hospital in Hong Kong. SUBJECTS 204 nulliparous women aged 16-42 (mean 23) years, who requested termination of a pregnancy of gestational age 56-84 (mean 67) days. 21 additional women were excluded from the analysis because of deviations in protocol or missing data. INTERVENTION 3 hours prior to vacuum aspiration, the women received either oral misoprostol (43 at the 200 μg dose and 40 at the 400 μg dose) or vaginal misoprostol (40 at the 200 μg dose and 37 at the 400 μg dose) plus a placebo for the alternate route, or both placebos (n = 44). MAIN OUTCOME MEASURES Pre-operative cervical dilatation, cumulative force (sum of peak forces required to enter the internal cervical os with dilators from 3 to 8 mm), blood loss, side-effects. MAIN RESULTS At the start of the procedure, the median (range) cervical dilatation was 5.5 (2-8) mm in the placebo group. In all four misoprostol groups, it was significandy higher (P < 0.01): 6.0 (5-8) mm with oral 200 μg, 7.5 (5-8) mm with oral 400 μg, 7.0 (3-8) mm with vaginal 200 μg, and 7.0 (3-8) mm with vaginal 400 μg. Within the oral groups, the 200 μg dose was less effective than the 400 μg dose (P < 0.05), but there was no significant difference among the oral 400 μg dose and the two vaginal doses. The median cumulative force required was 48 (3-248) N in the placebo group, 26 (1-77) N in the oral 200 μg group, 19 (1-101) N in the oral 400 μg group, 17 (1-102) N in the vaginal 200 μg group, and 22 (5-71) N in the vaginal 400 μg group (P < 0.05, placebo vs each misoprostol group, NS among misoprostol groups). The median blood loss was 100 ml in the placebo group and 50 mL in each of the misoprostol groups (P < 0.05). More women who received misoprostol experienced prc-operativc side-effects than those who received placebo, with the most common being abdominal pain (7-22% of women) and vaginal spotting (5-15%) (NS among misoprostol groups). No woman passed tissue prior to the procedure. There was no significant difference among groups in the duration of post-operative bleeding (median 5.0-6.8 days). CONCLUSION Both oral and vaginal misoprostol, when administered at doses of 200 or 400 μg 3 hours prior to vacuum aspiration of first trimester pregnancy in nulliparous women, were more effective than placebo in increasing cervical dilatation and reducing the force required to enter the cervical os. A dose effect was observed with oral misoprostol, but not with vaginal misoprostol. © 2000 Harcourt Publishers Ltd.