Is Induced Abortion a Risk Factor in Subsequent Pregnancy?

Abstract

The effect of elective pregnancy termination on the incidence of premature births or small-for-gestational-age (SGA) newborns in subsequent pregnancies is unclear. This retrospective cohort study assessed the influence of a history of pregnancy termination on the risk of pregnancy, frequency of premature births, and neonatal biometrics among 247,593 singleton primaparous women. Between 1998 and 2000, perinatal statistics for these women were obtained from the databases of 8 German federal states and analyzed. Women who had 1 or more previous elective pregnancy terminations based on physician interview comprised the study group; the control group included women with no history of previous terminations. The results were adjusted for confounding variables.

The adjusted data show a trend for increased preterm birth (≤36 weeks of gestation) and early preterm birth (≤31 weeks of gestation) among study group women aged 18 to 20, 28 to 30, and 37 to 42 years, but the increased rate of prematurity was statistically significant only for the cohort aged 28 to 30 years. Women in this age cohort with a history of 1 or ≥2 previous elective pregnancy terminations had prematurity rates of 7.8% and 8.5%, respectively, in comparison to the control group rate of 6.5% (P < 0.001). The risk of premature birth increased with the number of earlier induced terminations. A history of previous terminations had no effect on the frequency of SGA newborns. The investigators conclude from these data that previous elective pregnancy terminations should be considered a risk factor for premature birth in subsequent pregnancies but not for SGA newborns.