Demographic, lifestyle, and reproductive risk factors for ectopic pregnancy

DES Daughters have a much higher risk of EP,
Fertility and sterility, 2018


To evaluate the relationship between demographic, lifestyle, and reproductive factors and the risk of ectopic pregnancy (EP).

Prospective cohort.

United States.

Nurses’ Health Study II cohort comprising 41,440 pregnancies from 22,356 women.

Demographic, lifestyle, and reproductive factors self-reported in 1989 then updated every 2 years. Multivariable log-binomial regression models with generalized estimating equations were used to estimate adjusted risk ratios (aRR).

Ectopic pregnancy.

Incident EP was reported in 411 (1.0%) pregnancies. Former and current smokers had 1.22 (95% confidence interval [CI], 0.97-1.55) and 1.73 (95% CI, 1.28-2.32) times, respectively, the risk of EP compared with never smokers. The risk of EP 10 years after quitting was similar to never smokers (aRR 0.90; 95% CI, 0.60-1.33). Women consuming ≥10 g/day of alcohol had 1.50 (95% CI, 1.08-2.09) times the risk of EP compared with never consumers. In utero exposure to diethylstilbestrol (aRR 3.55; 95% CI, 2.51-5.01), earlier initiation of oral contraceptives (aRR 2.64; 95% CI, 1.70-4.09 for <16 years vs. never), intrauterine device use (aRR 3.99; 95% CI, 2.06-7.72), or history of infertility (aRR 3.03; 95% CI, 2.48-3.71) or tubal ligation (aRR 16.27; 95% CI, 11.76-22.53) also were associated with a higher risk of EP.

Women who were current or former smokers, consumed ≥10 g/day of alcohol, were exposed to diethylstilbestrol in utero, initiated oral contraceptives at earlier than age 16 years (which may be a marker of riskier sexual behaviors), and who had a history of infertility, intrauterine device use, or tubal ligation had a higher risk of EP.


  • Demographic, lifestyle, and reproductive risk factors for ectopic pregnancy, Fertility and sterility, NCBI PubMed PMID: 30503132, 2018 Dec.
  • Featured image : Transvaginal ultrasound images of an intrauterine pregnancy (IUP) and ectopic pregnancy. (A) An IUP at 6 weeks. The central dark area is the intrauterine gestational sac and within the sac is a circular ringed structure that is the yolk sac. The small oval structure below the yolk sac is the fetus. (B) An ectopic pregnancy. To the right of the image is the normal uterus and to the left of the uterus is the doughnut-shaped ectopic pregnancy – credit BMJ Faculty of Sexual & Reproductive Healthcare of the Royal College of Obstetricians & Gynaecologists.

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