title: Risk factors for ectopic pregnancy. A population-based study.
abstract: To evaluate the association between ectopic pregnancy and 22 potential risk factors, we conducted a population-based case-control study. The investigation included 274 cases diagnosed from 1935 through 1982 in residents of Rochester, Minn, and 548 matched controls selected from live-birth deliveries. Risk factor information documented prior to the last index menstrual period was obtained via medical record abstract. Univariate matched analyses revealed nine variables associated with a significantly elevated relative risk of ectopic pregnancy. Following conditional logistic regression, four variables remained as strong and independent risk factors for ectopic pregnancy: current intrauterine device use (relative risk, 13.7; 95% confidence interval, 1.6 to 120.6), a history of infertility (relative risk, 2.6; 95% confidence interval, 1.6 to 4.2), a history of pelvic inflammatory disease (relative risk, 3.3; 95% confidence interval, 1.6 to 6.6), and prior tubal surgery (relative risk, 4.5; 95% confidence interval, 1.5 to 13.9). Theoretically, any condition that prevents or retards migration of the fertilized ovum to the uterus could predispose a woman to ectopic gestation. Further research is needed to clarify the impact of other potential risk factors in the etiology of ectopic pregnancy.
authors.affiliation: Reproductive Health, Centers for Disease Control, Atlanta.
authors.forename: P A
authors.initials: PA
authors.lastname: Marchbanks
authors.forename: J F
authors.initials: JF
authors.lastname: Annegers
authors.forename: C B
authors.initials: CB
authors.lastname: Coulam
authors.forename: J H
authors.initials: JH
authors.lastname: Strathy
authors.forename: L T
authors.initials: LT
authors.lastname: Kurland
mesh_terms: D000293:Adolescent; D000328:Adult; D003627:Data Interpretation, Statistical; D004812:Epidemiologic Methods; D005187:Fallopian Tubes / Q000601:surgery*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000150:complications*; D007434:Intrauterine Devices / Q000009:adverse effects*; D008910:Minnesota; D000292:Pelvic Inflammatory Disease / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors