Randomised controlled trial of the efficacy of misoprostol used as a cervical ripening agent prior to termination of pregnancy in the first trimester

Background. Misoprostol is being used increasingly in clinical practice for cervical ripening in first-trimester abortions, but because of lack of goo d evidence of its effectiveness, administration consensus has not been reac hed on dosage, route of administration, time of administration preoperative ly and gestational age group. In this study we tested the hypothesis that s elf-administration of 600 mu g vaginal misoprostol is feasible and when use d 2 - 4 hours pre-operatively results in sufficient cervical dilatation to make suction curettage easier. Methods. A double-blind, randomised, placebo-controlled trial was undertake n. Two hundred and seventy-eight women scheduled for termination of pregnan cy of up to 12 weeks' duration by manual vacuum aspiration were assigned to receive either 600 mu g misoprostol pre-operatively, or placebo. The achie vement of 'satisfactory' (greater than or equal to 7 mm) baseline cervical dilatation after 2 - 4 hours was evaluated as the primary outcome. Secondar y outcome measurements included ease and duration of the procedure. Side-ef fects such as preoperative bleeding, gastro-intestinal complaints and pain as well as adverse events were noted in all cases. Findings. Self-administration of vaginal misoprostol was successful in all women and 273 women were evaluated for main end-points. A significantly lar ger proportion of patients in the treatment group reached cervical dilatati on of greater than or equal to 7 mm (67.3% v. 30.9%, P < 0.0001). The side- effects were minimal and comparable in the two groups. In the treatment gro up the mean procedure duration was significantly shorter (220 seconds v. 32 1 seconds, P = 0.0013) and the procedure was more likely to be rated by the operator as 'easy' (81.8% v. 63.3%, P = 0.0082). This resulted in a signif icant reduction in treatment failure in the < 70-day gestation group (5.0% v. 14.7%, P=0.005). Conclusion. It is feasible, safe and effective for 600 mu g misoprostol to be self-administered vaginally 2 - 4 hours preoperatively for cervical prim ing prior to manual vacuum aspiration. Further research is needed to establ ish optimal use in the first trimester and to determine patient acceptance.