EPIDEMIOLOGY OF REPEAT ECTOPIC PREGNANCY - A POPULATION-BASED PROSPECTIVE COHORT STUDY

Objective: To study infectious pathology at index ectopic pregnancy an d to determine what other factors predispose a woman to repeat ectopic pregnancy. Methods: All women (n = 697) with their first (index) ecto pic pregnancy histologically verified between January 1, 1978, and Dec ember 31, 1993, at the only two hospitals in one Norwegian county were eligible. Included were permanent residents of the county who were 37 years of age or younger and who had not had tubal surgery before the index pregnancy. When the study closed on November 1, 1994, the partic ipants had been observed prospectively for fertility events from appro ximately 1 to 17 years. Included in the final analyses were 353 women who had from one to five natural conceptions, for a total of 555 pregn ancies. Chi-square test was used in univariate analysis, and the gener alized estimating equations approach was used to analyze correlated re sponses and covariates that changed over time. Results: Pregnancy orde r is the stronger correlate of subsequent ectopic pregnancy. The frequ ency of repeat ectopic pregnancy decreased by one-third for each pregn ancy from the first to the third pregnancy. The odds of having another ectopic pregnancy were nearly three times higher for women with a dia gnosis of infectious pathology than for women who had no infectious pa thology. Other correlates of repeat ectopic pregnancy include age 24 y ears or younger at first ectopic pregnancy, history of repeat ectopic pregnancy, initiation of infertility work-up, and conception with an i ntrauterine device at index pregnancy. Method of surgery was not assoc iated with repeat ectopic pregnancy. Conclusion: The most crucial repr oductive event after first ectopic pregnancy is the first event to occ ur. Women who have experienced two ectopic pregnancies should be consi dered candidates for assisted reproduction.