Influence of induced abortion on gestational duration in subsequent pregnancies.

We studied the effect of previous induced and spontaneous abortion on gestational duration in subsequent pregnancies in 12 obstetric departments in the Netherlands. Only primiparae were studied. Of 504 women who had had a previous induced abortion, 18 (3.6%) delivered before 32 weeks' gestational age. Forty of 1313 women with a history of spontaneous abortion (3.0%) and 259 of 12 678 women with no history of abortion (2.1%) also delivered before 32 weeks. The differences between the three groups were not significant. In the Netherlands there are no significant indications that spontaneous midtrimester abortions or premature deliveries are caused by a previous induced abortion.