Oral versus vaginal misoprostol for cervical priming in first-trimester abortion: a randomized trial

The objective of this study was to compare the oral and vaginal administration of misoprostol for cervical priming before surgical abortion up to 63 days' gestation. A total of 900 pregnant women, with ages ranging from 18 to 42 years, who asked for pregnancy termination, were included in this study. Women were randomly allocated to one of the following groups: oral administration of 400 microg misoprostol, 8 h before aspiration; and vaginal self-administration of 400 microg misoprostol, 4 h before aspiration. During admission, all subjects were checked on a 15-min basis. The preoperative cervical dilatation achieved was the main outcome assessed. The cervix was dilated (Hegar > or = 8) in 348 (78%) subjects from the oral treatment group and in 391 (87%) women from the vaginal treatment group; this difference was statistically significant (p = 0.0004). The mean dilatation achieved in the oral treatment group was 8.1 mm (SD 1.6 mm) and it was 8.5 mm (SD 1.5 mm) in the vaginal treatment group; this difference was statistically significant (p = 0.0001). The frequencies of side-effects such as nausea, vomiting, diarrhea and chills reported by women from the vaginal misoprostol group were 10, 8, 18 and 4 times lower, respectively, than those reported by subjects from the oral misoprostol group. In conclusion, vaginal self-administration of misoprostol was the best administration route, as it obtained the same or greater priming effectiveness of the cervix in half the time with a much lower frequency of side-effects.