Mifepristone-induced abortion and birth weight in the first subsequent pregnancy

To assess the effect of a medically induced abortion (MA) on birth weight in the first subsequent pregnancy.

Pregnant women who had had a MA, a surgical abortion (SA), or primigravidas with no history of abortion (NA), were recruited for a prospective cohort study between July 1998 and February 2001. The sample for the present analysis included 12995 singleton live births at term.

The overall incidence rate of low birth weight (LBW) was 1.0%. The rates of LBW in the MA, SA, and NA groups were 1.0%, 0.9%, and 1.2, respectively. There were no significant differences in LBW rates between the MA and SA groups, neither between the MA and NA. Logistic regression analysis was used to estimate the effects of MA on birth weight, and we found no relationship between risk of LBW and MA.

We did not find a statistically significant relationship between a history of one medically induced abortion and LBW for the first subsequent term pregnancy.