Induced abortion and spontaneous fetal loss in subsequent pregnancies.

The effect of induced abortion on spontaneous pregnancy loss in subsequent pregnancies was studied based on 3,416 pairs of matched data in a follow-up investigation. Pregnancy outcome was examined also in relation to abortion procedure, gestation length at time of abortion, and number of previous abortions. In general there was no significant association between prior induced abortion and risks of pregnancy loss with the relative risks of 1.10, 0.88, and 0.81 for the first to third trimester respectively. A slight increase of first-trimester spontaneous loss was noted with the D&C/Suction procedure and early induced abortion (less than 9 weeks). The D&C procedure was associated with non-significant increase of second-trimester loss with the relative risk of 1.59.