Comparative study of extra-amniotic prostaglandin F2 alpha infusion and increasing intravenous oxytocin for termination of second trimester missed abortion.

Extra-amniotic infusion of prostaglandin F2 alpha (PGF2 alpha) and intravenous (IV) oxytocin in increasing doses were compared in a retrospective study to establish the efficacy of the two methods for termination of pregnancies with second trimester missed abortion. Sixty women with this complication underwent pregnancy termination, 28 by extra-amniotic infusion of PGF2 alpha and oxytocin augmentation, if necessary, and 32 by IV oxytocin in increasing doses. All patients in the PGF2 alpha group aborted within 24 hours from onset of infusion and seven of them needed oxytocin augmentation. There were nine failures in the oxytocin group and the other 23 aborted within 17 hours. The mean (plus or minus standard error of the mean) induction-abortion interval was significantly less in the oxytocin group (6.9 +/- 3.4 hours) than in the PGF2 alpha group (12.6 +/- 5.7 hours) p < 0.001. Eight patients in the group had mild side effects, such as nausea, flushes or transient hypotension. Uterine hypertonus was observed in two women receiving PGF2 alpha and treated by temporary interruption of the infusion. In the oxytocin group, one patient had coagulation disturbances and one, hemorrhage. We conclude that extra-amniotic PGF2 alpha infusion is more effective than IV oxytocin in increasing doses, for termination of second trimester missed abortion, but takes effect more slowly. We can assume that further use of IV oxytocin immediately after termination of the PGF2 alpha administration can shorten the induction-abortion interval.