Successful live birth following laparotomy for an interstitial heterotopic pregnancy after in vitro fertilization: a case report

Heterotopic pregnancy, the simultaneous existence of intrauterine and extrauterine gestations, is a rare but life-threatening condition. Its incidence is significantly higher in pregnancies conceived via assisted reproductive technologies (ART) compared to natural conception. The interstitial location is the most perilous variant, posing a high risk of uterine rupture and catastrophic hemorrhage. We present the case of a 36-year-old Waala woman, Gravida 1 Para 0, with primary infertility due to a tubal factor and a history of myomectomy, who underwent in vitro fertilization (IVF). Following a fresh blastocyst transfer, an initial transabdominal ultrasound at 6 weeks confirmed a single viable intrauterine pregnancy. However, a follow-up scan at 10 weeks and 4 days of gestation revealed a viable right interstitial heterotopic pregnancy. The diagnosis was initially challenging because enlarged ovaries with multiple corpora lutea from recent ovarian stimulation limited adnexal visualization. The asymptomatic patient underwent an emergency laparotomy for excision of the 4 × 4 cm right interstitial gestation. The procedure was successful, with careful preservation of the ongoing intrauterine pregnancy. Her chronic hypertension was subsequently complicated by superimposed preeclampsia, manifested by worsening blood pressure control and new-onset proteinuria requiring antihypertensive therapy. At 36 weeks of gestation, elective cesarean delivery was performed because of the hypertensive complication and the prior myomectomy/interstitial resection, delivering a healthy female neonate weighing 2,600 g with Apgar scores of 8, 9, and 9 at 1, 5, and 10 minutes, respectively. This case highlights the critical importance of maintaining a high index of suspicion for heterotopic pregnancy in post-IVF patients, even after an early scan confirms an intrauterine gestation. Diagnostic difficulties posed by ovarian changes post-stimulation necessitate meticulous and repeated sonographic evaluation. Prompt diagnosis and decisive surgical management can lead to favorable maternal and neonatal outcomes.