Characteristics of pregnant women who report previous induced abortions.

Associations between previous induced abortion and demographic and health factors in pregnancy were measured in 9 874 women who gave birth and who had been interviewed during pregnancy. Previous abortion was most rare among women having their first baby and increased with increasing birth order up to the fourth, thereafter decreasing. It was positively correlated with maternal age and negatively with age at marriage. There was no effect of years of schooling, when other variables were taken into account, but there were significant differences between ethnic groups, abortion being commonest among Jewish women from North African countries and more prevalent in those from western and Asian countries than in the second-generation Israel-born or in Arab women.Women who reported abortions were less likely to be strict as regards religious observance and less likely to have had a previous stillbirth or child death, other variables being equal. They were more likely to be smokers or former smokers and to be delivered of their babies in certain obstetric units. They more often reported vomiting, bleeding, and medication in early pregnancy. On the other hand, there was no significant association with diabetes, anaemia, blood groups, or season of birth.The findings show that women reporting previous induced abortions differ significantly from other pregnant women in a wide range of demographic and health characteristics. Such women may also be biased for complications of pregnancy and outcome, particularly if selected from a clinic population. Observations that indicate a deleterious effect of induced abortions on subsequent pregnancy outcomes must therefore be interpreted with considerable caution.