Emergency Cesarean Delivery Complicated by Massive Postpartum Hemorrhage Revealing an Undiagnosed Unicornuate Uterus: A Case Report

Increased first-trimester nuchal translucency (NT) may be associated with chromosomal, genetic, and structural abnormalities, although some pregnancies progress with normal invasive testing and reassuring interval imaging. This case involved a 32-year-old primigravida referred at 12+5 weeks’ gestation following the identification of markedly increased NT measuring 5.6 mm, with associated body wall oedema. Chorionic villus sampling demonstrated normal fluorescence in situ hybridisation (FISH) and chromosomal microarray results, while subsequent antenatal imaging showed resolution of the body wall oedema without identifiable fetal structural anomalies. Later in pregnancy, gestational hypertension developed, requiring antihypertensive therapy and induction of labour at 38 weeks. Following failure to progress and an abnormal cardiotocograph, an emergency caesarean section was performed. Intraoperatively, a previously undiagnosed unicornuate uterus with an absent left fallopian tube, ovary, uterine artery and ureter was identified. Delivery was complicated by uterine angular extension, severe uterine atony, persistent haemorrhage and difficult pelvic anatomy, progressing to massive postpartum haemorrhage with an estimated cumulative blood loss of 10 L. Despite escalation through uterotonics, compression sutures, vascular ligation, vaginal packing and Bakri balloon tamponade, definitive haemostasis required hysterectomy, excision of the cervical remnant, right internal iliac ligation, and multidisciplinary surgical input. The patient required massive transfusion and intensive care admission but recovered postoperatively. This case highlights the complexity of counselling pregnancies with isolated increased NT despite normal genetic testing and illustrates how previously occult Müllerian and urinary tract anomalies may only become evident during obstetric emergency surgery, profoundly influencing haemorrhage control and operative risk.