EP11.19: A rare presentation: suspected hemolytic uremic syndrome in early pregnancy

Hemolytic uremic syndrome (HUS) is a rare pregnancy complication (1/25,000) with microangiopathy as a hallmark feature. Differentiating HUS from other obstetric complications poses a significant challenge. We present the case of a patient at 17 weeks gestation presenting with microangiopathy. A 38 year old pregnant woman, G4P1A3 with prior miscarriages, an ectopic pregnancy, and one Caesarean section at term, presented at 17 weeks with cephalea, vomiting, and visual blur (4 days). Current pregnancy was IVF induced and the patient reported enoxaparin and aspirin use for thromboprophylaxis. Past medical history was unremarkable for hypertension, allergies, or substance abuse, although she reported recent food poisoning. Physical examination revealed signs of microangiopathy, including pale conjunctivae, palpebral edema, ecchymosis, and proteinuria. Blood pressure was normal (100/80 mmHg). Ultrasound confirmed fetal viability. Laboratory findings were concerning for microangiopathic hemolytic anemia with a hemoglobin of 6.8 g/dL, a platelet count of 36,000/μL, and a markedly elevated creatinine level of 637.79 μmol/L. Liver function tests were within normal limits. Atypical HELLP syndrome or HUS were suspected given the clinical presentation and laboratory abnormalities. The patient received transfusions and underwent Caesarean section due to ongoing concerns, the surgery was complicated by uterine atony, requiring medical and vascular procedures to achieve hemostasis. Postoperatively, deteriorating renal function required hemodialysis. The diagnosis of HUS was ultimately suspected due to the persistent renal dysfunction despite delivery and the absence of ADAMTS testing, which was unavailable. In conclusion, this case underscores the importance of including HUS in the differential diagnosis for pregnant women presenting with anemia, thrombocytopenia, and acute renal failure. Early diagnosis is crucial due to the potential for severe maternal complications.