In a retrospective study, a group of 137 women with legal abortion in their 1st pregnancy was compared with a group of 133 women with spontaneous abortion (before 28 wk) and a group of 129 women who had a delivery (beyond 28 wk) in their 1st pregnancy. Three cases of ectopic pregnancy were recorded in the 2nd pregnancy in the legal abortion group, none in the other groups. The delivery group showed the best reproducitve performance, while the spontaneous abortion group had the highest frequency of early abortion and the induced abortion group the highest frequency of late spontaneous abortion and premature delivery, and in addition a trend towards earlier spontaneous onset of labor in their 2nd pregnancy. There was a conspicuous decline of the reproductive performance in the 3rd and 4th pregnancy of the induced abortion group and a highly significant increase of the rate of late abortion, compared with the overall rate of late abortion in the department. The induced abortion group showed an increased rate of spontaneous primary and premature rupture of the membranes and also a definite trend towards lower weight of the newborn, especially beyond 41 wk of pregnancy. There was a close correlation between induced abortion in girls below 17 yr of age and repeated abortion and/or unmarried state in the 2nd pregnancy. A significant correlation was revealed between early menarche and legal abortion in the 1st pregnancy and also between early menarche and unmarried state in the 1st pregnancy as found in a random series of 250 1st pregnant women.