Oxytocin- or low-dose prostaglandin F2 alpha-infusion for stimulation of labor after primary rupture of membranes. A prospective, randomized trial

Abstract

One hundred consecutive women with singleton pregnancies and primary rupture of membranes (PROM) after 36 weeks of gestation were included in a prospective, randomized trial of intravenous infusion of oxytocin (up to 30 mIU/min) versus low-dose prostaglandin F2 alpha(PGF2 alpha, up to 6.0 micrograms/min). Cesarean section was performed in 12 patients because of suspected disproportion or intra-uterine asphyxia. Effective contractions or labor progress failed to become established within 8 hours in another 4 women stimulated with PGF2 alpha and 2 stimulated by oxytocin. The stimulation delivery time (hours) for the remaining 82 women treated with PGF2 alpha or oxytocin, respectively was 8.7 against 12.1 for initial Bishop score less than 5 (p less than 0.01), (Mann-Whitney test), 7.2 vs. 7.1 for Bishop score 5-8 and 5.7 vs. 4.2 for Bishop score greater than 8. Patients with initial Bishop score less than 5 seemed to need analgetics less often when treated with PGF2 alpha than with oxytocin. Frequencies of side effects and instrumental deliveries as well as the fetal outcome were similar for the two treatment schedules. The results of the study suggest that low-dose PGF2 alpha infusion may be the more appropriate treatment for women with an unfavorable initial Bishop score.