Challenges of Interstitial Ectopic Pregnancy in a Fibroid Uterus: A Case Report

Interstitial ectopic pregnancy (IEP), although a rare clinical entity representing 2%-6% of all ectopic pregnancies, is associated with higher morbidity and mortality than other types of ectopic pregnancy, compounded by distinct challenges in diagnosis and management.

A 40-year-old multiparous female (G7P3M2E1) presented for routine early pregnancy ultrasound due to a previous history of pregnancy of unknown location (presumed tubal ectopic pregnancy). Transvaginal ultrasound scan did not identify any intrauterine gestational sac, despite β-hCG levels elevated at 19,009 iU/L. Imaging was noted to be technically challenging due to the presence of a large fundal fibroid. Serial measurement noted a drop in β-hCG levels and the patient was initially managed conservatively as a pregnancy of unknown location. After becoming acutely unwell, ruptured ectopic pregnancy was the primary differential diagnosis. The patient underwent emergency laparoscopy, where a right IEP was diagnosed with associated large haemoperitoneum. Right superficial cornuostomy and right salpingectomy were performed, and the patient had an excellent recovery.

Challenges in diagnosis and management of IEP are recognised; however, these are further complicated in situations where there is coexistence of other uterine pathology such as large uterine fibroids. This case highlights that with appropriate expertise, safe and successful surgical management of ruptured IEP is possible using a laparoscopic approach, with cornuostomy and ipsilateral salpingectomy.