Misoprostol for pre-term labor induction in the second trimester: Role of medical history and clinical parameters for prediction of time to delivery.

Abstract

Serious fetal malformations and/or chromosome aberrations detected by modern diagnostic tools in early pregnancy require discussions on induced abortion with pregnant women. Competent counseling includes prediction of the time needed for the whole abortion process. In an attempt to refine our predictions, we evaluated the impact of 11 medical history and clinical variables on time to delivery. We performed a retrospective chart analysis on 79 women submitted for pre-term abortion because of fetal anomalies. Abortion was induced by vaginal application of misoprostol (prostaglandine E1, Cytotec™, Pfizer, New York, USA). We investigated 11 medical history and clinical variables for their impact on the percentage of women delivering within 24 hours (primary endpoint) and on the mean induction-delivery time interval (secondary endpoint). Fifty-three percent (42/79) of women delivered within 24 hours; 83.6% (66/79) delivered within 48 hours. A total of 83.3% of women with a history of late abortion delivered within 24 hours, whereas 50.7% without this history did. Mean induction-delivery time interval was 12.3 hours versus 35.5 hours, respectively. For history of early abortion, the figures were 65.2% versus 48.2% for delivery within 24 hours and 15.6 hours versus 32.5 hours for mean induction-delivery time interval. Current weight of fetus >500 g, weight of last previous newborn of ≤3500 g, previous pregnancies, premature rupture of membranes, and an elevated CRP of >0.5 mg/dL also cut time to delivery. Surprisingly, maternal and gestational age had no remarkable or consistent impact on the mean induction-delivery time interval. None of the differences reached statistical significance. Eighty-three percent of women needed 1000 μg or less for successful delivery. Neither variables of medical history nor specific clinical variables allow for precise prediction of time to delivery in the second trimester. Certain parameters, however, show a trend to reduce the induction-delivery time interval. Our results might serve as initial guidance for patient counseling.