Presented here is the pregnancy outcome of 2,081 women who had one or more previous induced abortions compared with the outcome of 4,098 matched control subjects without a history of abortion. Data were collected from records and interviews of women delivering spontaneously at nine California hospitals during a 16-month period, 1976 to 1978. Women with a history of previous induced abortion showed a small but statistically significant increase in incidence of subsequent pregnancy failure. The increased risk associated with previous abortion was substantially smaller than the increase associated with several other social, economic, and behavioral indicators measured at the same time.
PIP: The pregnancy outcomes of 2081 women who had 1 or more previous induced abortion were compared with the outcomes of 4098 matched controls without a history of abortion. The data were collected from 9 California hospitals during a 16-month period, 1976 to 1978. Chi-square tests of 2-by-2 tables and multivariate analysis (multiple logistic regression) were performed. Mean ages of case and control subjects were 24.1 and 24.0 respectively. One prior spontaneous abortion had occurred in 8.4% of the cases and in 8.1% of controls. There were no differences in the outcomes rates of ectopic pregnancy, spontaneous abortion ( 20 weeks), congenital anomalies and infants of low birthweight. A small but statistically significant increase in incidence of subsequent pregnancy failure was observed in women with a history of previous abortion. 6 other variables in the study demonstrated a stronger association with pregnancy failure, as indicated by the odds ratio, with higher significance levels for each. A parodoxical finding was the positive relation of good prenatal care and high economic status with pregnancy failure. A possible explanation was that the study included many women with Spanish surnames who tended to have late or no prenatal care and fall into the low-income category, but throughout the study showed a significantly better than average outcome.