Tubal stump pregnancy after salpingectomy-Does the time interval from surgical intervention to conception matter?

Aim: Ectopic pregnancy implantation on the tubal stump after salpingectomy is a rare location for extrauterine pregnancy, whose pathogenesis is still unknown. The purpose of this study was to examine whether the time interval elapsed from salpingectomy may predispose the embryo to implantation on the tubal stump in the next pregnancy subsequent to tube removal.
Methods: Nine women operated for stump pregnancy (study group) between 2008 and 2019 were retrospectively identified. For each case in the study group, 12 consecutive cases that underwent laparoscopic salpingectomy constituted the control group. A sample size of 100 control patients was calculated to achieve statistical power (97.8%) and an α of 0.05. The control groups were triple-matched with the study group for patients' age, indications for salpingectomy (tubal pregnancy or hydrosalpinx prior to in vitro fertilization treatment) and mode of conception of the subsequent pregnancy following salpingectomy.
Results: Nine women underwent surgery for stump pregnancy during the study period. All women had a surgical history of laparoscopic salpingectomy. The time interval from prior salpingectomy to subsequent pregnancy was significantly shorter in study group than in the control group (4.3 ± 2.1 months vs. 15.6 ± 13.7 months, respectively, p = 0.016).
Conclusion: A possible association between the short time interval from prior salpingectomy to ectopic implantation on the tubal stump in the subsequent pregnancy was found. The clinical implications of these findings and in particular whether patients should be advised to wait at least 4 months from the salpingectomy to the subsequent pregnancy remain unclear.
(© 2021 Japan Society of Obstetrics and Gynecology.)