Ectopic pregnancy and prior induced abortion.

ABSTRACT

As part of the Women's Health Study, a case-control study conducted in nine cities in the United States, women hospitalized with an ectopic pregnancy and women hospitalized with non-gynecologic, medical or surgical diagnoses were interviewed concerning past reproductive history. There were 462 women meeting eligibility criteria in the ectopic pregnancy case group and 2326 women meeting the criteria for the control group. After adjustment for a number of possible confounders, the relative risk of ectopic pregnancy for women with a history of one induced abortion was 1.0 (95% confidence limits 0.5 to 1.8) and was 0.9 (95% confidence limits 0.8 to 1.1) for women with a history of two or more prior induced abortions. These results suggest that prior induced abortion does not significantly increase the risk of subsequent ectopic pregnancy.

ABSTRACT

PIP A case-control study conducted in 9 US cities as part of the Women's Health Study suggests that prior induced abortion is not associated with a subsequent markedly increased risk of ectopic pregnancy. Study subjects included 462 women hospitalized with an ectopic pregnancy at 16 hospitals in 1976-78. Controls included 2326 women hospitalized during the same period with nongynecologic, medical, or surgical diagnoses. After adjustment for several confounders that are known risk factors for ectopic pregnancy (i.e., race, a history of prior pelvic inflammatory disease, and prior ectopic pregnancy), the relative risk of ectopic pregnancy for women with a history of 1 induced abortion was 1.0 (95% confidence limits, 0.5-1.8). Among women with a history of 2 or more induced abortions, the relative risk of ectopic pregnancy was 0.9 (95% confidence limits, 0.8-1.1). Several earlier studies have suggested a potential increased risk of ectopic pregnancy among women with a history of abortion; however, these studies have generally failed to control for important risk factors, have involved populations from countries that are substantially different demographically from the US, and have included substantial numbers of women whose abortion procedures were illegal.