[Artificial interruption of pregnancy in primigravidae as a risk-factor for further pregnancies (author's transl)].

In order to study the effects of abortion on subsequent pregnancy, 13,144 secundigravidae were studied. In 879 of those women the 1st pregnancy had ended in miscarriage, in 820 it ended in abortion, in 25 in tubal pregnancy, in 7 in molar pregnancy, in 294 in premature delivery, and in 11,119 in normal delivery at term. Of the complications of early pregnancy, threatened abortion was the most common. 13.8% of the women who had miscarried previously experienced this complication, as did 9.1% of those who had had an abortion, 9.1% of those who delivered prematurely, and 3.6% of women who experienced normal deliveries. Other complications were equally common in all 4 subgroups. In the 2nd half of pregnancy, miscarriage was about twice as common among women who had had an abortion or miscarriage during their 1st pregnancy as it was in women whose 1st pregnancy was not interrupted. Furthermore, women who had miscarried or aborted the 1st pregnancy were twice as likely as women who delivered at term to give birth to infants weighing less than 2500 gm. Women who had delivered the 1st pregnancy prematurely were about 4 times as likely to have a subsequent premature delivery as were women whose 1st pregnancies ended at term. Thus it appears that interruption of a 1st pregnancy - either by abortion or miscarriage - significantly increases the risk of miscarriage in a subsequent pregnancy.