Primary ovarian pregnancy after postpartum bilateral tubal ligation: a case report.

Background: Primary ovarian pregnancy constitutes <1% of ectopic gestations. Likewise, bilateral tubal ligation failure is uncommon, occurring in approximately 1% of tubal sterilization procedures. Should pregnancy occur after bilateral tubal ligation, of every 3 such pregnancies, 1 will be an ectopic. The incidence of ovarian pregnancy after tubal ligation has not been reported, but must be extremely rare.

Case: A 30-year-old, breast-feeding, white woman 6 months postpartum, with bilateral tubal ligation after delivery, developed acute right lower quadrant pain while excercising. Evaluation in the emergency room revealed rebound tenderness in the lower right abdomen, a positive beta-hCG level and ultrasound findings suspicious for a right ectopic pregnancy. Exploratory laparotomy revealed hemoperitoneum, previously ligated but otherwise-normal-appearing fallopian tubes, and a ruptured and bleeding right ovary. The pelvis was otherwise normal. Histology of the right ovarian wedge resection showed chorionic villi consistent with ovarian pregnancy. Both fallopian tubes were religated, and a review of the original tubal ligation histology confirmed tubal lumen in both segments.

Conclusion: While ectopic pregnancy is a known but rare risk of failed tubal sterilization, pregnancy involving the fallopian tube is usually reported after tubal ligation failure. The rarely seen primary ovarian pregnancy is usually associated with intrauterine contraceptive devices or occurs in patients with pelvic inflammatory disease. Ovarian pregnancies are associated with massive hemoperitoneum in women unaware that they are pregnant.