Rare Occurrence of Left Ampullary Ectopic Pregnancy After Ligation of the Left Fallopian Tube: A Case Report

PURPOSE: Ectopic pregnancy (EP) is rare among patients having received tubal ligation; in these cases, a fertilized ovum is implanted in the proximal tube stump. Distal tubal EP cases in patients having undergone ipsilateral tubal ligation and who have relatively intact contralateral adnexa are extremely rare. Here, we report a case of pregnancy in the distal stump of the ipsilateral fallopian tube following fallopian tubal isthmus ligation. CASE PRESENTATION: A 28-year-old woman was admitted after having experienced lower abdominal pain for 10 days and amenorrhea for 1 week and receiving a transvaginal color ultrasonography finding of a heterogeneous echo (2.1 × 1.2 × 1.4 cm) near the left ovary. The patient had a medical history of transvaginal left tubal ligation under single-port laparoscopy for a left hydrosalpinx. Postoperatively, the patient had undergone in vitro fertilization for assisted reproduction. After ovum retrieval, whole-embryo cryopreservation had been performed due to the ovarian hyperstimulation syndrome trend. This pregnancy was natural after embryo cryopreservation. After the patient was admitted, laparoscopic exploration revealed an elevated ampulla in the distal stump of the left fallopian tube. Left salpingectomy with removal of the ectopic pregnancy in the distal remnant tube was performed under the guidance of transvaginal single-port laparoscopy. Serum β-human chorionic gonadotropin levels gradually decreased. Thereafter, the patient underwent two cycles of frozen embryo transfer, both of which resulted in chemical pregnancies. CONCLUSION: This case suggests that gynecologists should pay attention to the possibility of fallopian tube ectopic pregnancy in the distal tubal segment post-tubal ligation.