Is induced abortion a risk factor in subsequent pregnancy?

Abstract

To determine whether a history of terminations of pregnancy influences subsequent pregnancies in terms of pregnancy risks, prematurity and neonatal biometrics. Based on the perinatal statistics of eight German federal states, data of 247,593 primiparous women with singleton pregnancies born between 1998 and 2000 were analyzed. The control group consisted of primiparous women without previous induced abortions. Maternal age was adjusted for. There was an overall trend towards an increased rate of preterm delivery at <or=36 weeks' gestation and early preterm delivery at <or=31 weeks' gestation in women who had previous pregnancy terminations. For the cohort of 28-30 years, the observed rates of prematurity in women with one and with >or=2 previous induced abortions were 7.8% and 8.5%, respectively, compared to 6.5% in the control population (P=0.015). Preceding terminations of pregnancy did not alter the rate of small-for-gestational-age newborns. Psychosocial stress and symptoms associated with prematurity such as cervical incompetence and vaginal bleeding before and after 28 weeks of gestation occurred more frequently in women with previous induced abortion compared to the control group (P<0.0001). The rate of preterm births increases with the number of preceding abortions. Similarly, symptoms associated with prematurity are more common. The rate of small-for-gestational-age newborns was not affected by preceding terminations of pregnancy.