A 34-year-old woman (G3 P0+2) booked at 6 weeks with a trichorionic triamniotic triplet pregnancy. She developed gestational proteinuria at 32 weeks and underwent elective Caesarean section at 34+4 weeks due to growth restriction and raised umbilical artery Doppler pulsatility index in two fetuses. The procedure was complicated by a 4.2L haemorrhage, necessitating a return to the operating theatre shortly after for a hysterectomy, with a total blood loss of 10L. Prophylactic dalteparin was omitted on the day of the hysterectomy and commenced on postoperative day 1. On postoperative day 2, clear fluid drainage from the abdominal drain site prompted a CT scan to investigate for urinary tract injury, which was excluded. However, imaging revealed an 8.5cm thrombus in the IVC extending from the infrarenal to suprarenal regions. An IVC filter was deemed unsuitable due to the risk of displacement into the right atrium, so anticoagulation with tinzaparin was initiated. Dosage adjustments were required due to thrombocytopenia secondary to HELLP syndrome, and lifelong warfarin therapy was later prescribed. A follow-up CT at three months confirmed complete thrombus resolution.