ABSTRACT

Introduction: Ectopic pregnancy refers to implantation of a gestation outside the endometrial cavity and remains a major contributor to early pregnancy morbidity. While ectopic pregnancies are typically unilateral, bilateral tubal implantation represents an uncommon clinical entity with an estimated incidence of approximately 1 per 200,000 pregnancies. Pregnancy occurring with an intrauterine device (IUD) in situ is uncommon; however, when conception occurs, the relative risk of ectopic implantation is increased. We report a rare case of bilateral tubal ectopic pregnancy associated with a copper IUD that was successfully managed with medical therapy.

Case Report: A 26-year-old nulligravid woman with a copper IUD in place since 2020 presented after two positive home pregnancy tests. She was asymptomatic, denying abdominal pain, vaginal bleeding, dizziness, or urinary complaints. Vital signs were stable, and laboratory studies were normal except for a serum β-human chorionic gonadotropin (β-hCG) level of 4655 mIU/mL. Transabdominal and transvaginal ultrasonography demonstrated a normal uterus without gross anatomical or structural defect and a correctly positioned IUD without an intrauterine gestational sac. Bilateral complex adnexal masses measuring 2.4 × 1.6 × 1.4 cm on the right and 2.9 × 1.7 × 2.2 cm on the left, each demonstrating peripheral vascularity, were highly suspicious for bilateral ectopic pregnancy. No significant pelvic free fluid was seen. The IUD was removed, and intramuscular methotrexate (MTX) (50 mg/m² ; 88.5 mg) was administered. Because the β-hCG level increased to 4924 mIU/mL on day 4, a second MTX dose was given. Serial β-hCG measurements subsequently declined appropriately, reaching 201 mIU/mL by day 17, confirming successful resolution without surgery or complications.

Conclusion: The uniqueness of this case lies in the occurrence of bilateral tubal ectopic pregnancy in an asymptomatic patient with a copper IUD who achieved successful medical resolution. Early recognition through meticulous ultrasonographic evaluation of both adnexa, combined with serial β-hCG monitoring and appropriate patient selection, permitted successful fertility-preserving medical management while avoiding surgery and its associated risks.