title: Ectopic pregnancy and prior induced abortion.
abstract: We compared the prior pregnancy histories of 85 multigravid women with an ectopic pregnancy and 498 multigravid delivery comparison subjects. We found a relationship between the number of prior induced abortions and the risk of ectopic pregnancy: the crude relative risk of ectopic pregnancy was 1.6 for women with one prior induced abortion and 4.0 for women with two or more prior induced abortions; however, use of multivariate techniques to control confounding factors reduced the relative risks to 1.3 (95 per cent confidence interval, 0.6-2.7) and 2.6 (95 per cent confidence interval, 0.9-7.4), respectively. The analysis suggests that induced abortion may be one of several risk factors for ectopic pregnancy, particularly for women who have had abortions plus pelvic inflammatory disease or multiple abortions.
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects*; D005260:Female; D006801:Humans; D010298:Parity; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000209:etiology*; D012306:Risk