Previous abdominal surgery and tubal pregnancy

To determine the role of previous abdominal surgery in tubal pregnancy risk, we compared 337 women diagnosed with tubal pregnancy during 1981-1986 with 893 population-based controls concerning their medical, reproductive, and sexual histories. After excluding types of abdominal surgery that involve the fallopian tubes directly and after adjusting for age, gravidity, and reference year, we found no increased risk for tubal pregnancy related to previous cesarean delivery (relative risk 0.6, 95% confidence interval 0.3-1.2), ovarian surgery (relative risk 1.2, 95% confidence interval 0.6-2.5), or removal of an unruptured appendix (relative risk 1.2, 95% confidence interval 0.7-2.2). An increased risk was noted for tubal pregnancy associated with previous ruptured appendix (relative risk 1.8, 95% confidence interval 0.6-5.5), but the increase was well within the limits of chance. With the possible exception of ruptured appendix, our study indicates that abdominal surgery that does not directly involve the fallopian tubes has little or no influence on the occurrence of tubal pregnancy.