The relationship between induced abortion and outcome of subsequent pregnancies.

We analyzed interview and record review data from 9,823 deliveries to evaluate the relationship between prior history of induced abortion and subsequent late pregnancy outcomes. Complications such as bleeding in the first and third trimesters, abnormal presentations and premature rupture of the membranes, abruptio placentae, fetal distress, low birth weight, short gestation, and major malformations occurred more often among women with a history of two or more induced abortions. A logistic regression analysis to control for multiple confounding factors showed that a history of one induced abortion was statistically significantly associated with first-trimester bleeding but with no other untoward pregnancy events, and a history of two or more induced abortions was statistically associated with first-trimester bleeding, abnormal presentations, and premature rupture of the membranes. While these relationships merit further research, the results of this study are largely reassuring. A history of one or more prior induced abortions does not appear to increase substantially the risk of adverse late outcomes of subsequent pregnancies.