Reproductive Outcomes Following Ectopic Pregnancy: Register-Based Retrospective Cohort Study

Background: We aimed to compare reproductive outcomes following ectopic pregnancy (EP) versus livebirth, miscarriage, or termination in a first pregnancy. Methods and Findings: A retrospective cohort study design was used. Scottish national data on all women whose first pregnancy occurred between 1981 and 2000 were linked to records of a subsequent pregnancy. The exposed cohort comprised women with an EP in their first pregnancy. There were three unexposed cohorts: women with livebirth, miscarriage, and termination of their first pregnancies. Any differences in rates of second pregnancy, livebirth, EP, miscarriage, or terminations and complications of a second ongoing pregnancy and delivery were assessed among the different exposure groups. A total of 2,969 women had an initial EP; 667,299 had a livebirth, 39,705 women miscarried, and 78,697 terminated their first pregnancies. Women with an initial EP had an increased chance of another pregnancy within 2 years (adjusted hazard ratio (AHR) 2.76 [95% CI 2.58-2.95]) or after 6 years (AHR 1.57 [95% CI 1.29-1.91]) compared to women with a livebirth. In comparison with women with an initial miscarriage, women who had an EP had a lower chance of a second pregnancy (AHR 0.53 [95% CI 0.50-0.56]). Compared to women with an initial termination, women with an EP had an increased chance of a second pregnancy (AHR 2.38 [95% CI 2.23-2.55]) within 2 years. Women with an initial EP suffered an increased risk of another EP compared to women with a livebirth (AHR 13.0 [95% CI 11.63-16.86]), miscarriage (AHR 6.07 [95% CI 4.83-7.62]), or termination (AHR 12.84 [ 95% CI 10.07-16.37]). Perinatal complications in a pregnancy following EP were not significantly higher than those in primigravidae or in women with a previous miscarriage or termination. Conclusion: Women with an initial EP have a lower chance of conception than those who miscarry but an increased risk of a repeat EP in comparison with all three comparison groups. A major limitation of this study was the inability to separate women using contraception from those who were intending to conceive.