Epidemiology of repeat ectopic pregnancy: a population-based prospective cohort study

To study infectious pathology at index ectopic pregnancy and to determine what other factors predispose a woman to repeat ectopic pregnancy.

All women (n = 697) with their first (index) ectopic pregnancy histologically verified between January 1, 1978, and December 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 participants had been observed prospectively for fertility events from approximately 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 pregnancies. Chi-square test was used in univariate analysis, and the generalized estimating equations approach was used to analyze correlated responses and covariates that changed over time.

Pregnancy order is the stronger correlate of subsequent ectopic pregnancy. The frequency of repeat ectopic pregnancy decreased by one-third for each pregnancy from the first to the third pregnancy. The odds of having another ectopic pregnancy were nearly three times higher for women with a diagnosis of infectious pathology than for women who had no infectious pathology. Other correlates of repeat ectopic pregnancy include age 24 years or younger at first ectopic pregnancy, history of repeat ectopic pregnancy, initiation of infertility work-up, and conception with an intrauterine device at index pregnancy. Method of surgery was not associated with repeat ectopic pregnancy.

The most crucial reproductive event after first ectopic pregnancy is the first event to occur. Women who have experienced two ectopic pregnancies should be considered candidates for assisted reproduction.