Postpartum Renal Cortical Necrosis Is Associated With Atypical Hemolytic Uremic Syndrome in Developing Countries

Pregnancy-related acute kidney injury is the most common cause of renal cortical necrosis (RCN). Atypical hemolytic uremic syndrome (aHUS) as a cause of RCN in pregnant/postpartum is underevaluated. In the current article, we describe a series of cases of pregnancy-related RCN.

All cases with acute kidney injury (AKI) in the setting of pregnancy and postpartum state were included. Diagnosis of RCN was made by contrast-enhanced computerized tomography (nonenhancing renal cortex, enhancing medulla, and no excretion of contrast medium) or on a renal biopsy. aHUS was diagnosed in the presence of microangiopathic hemolytic anemia (thrombocytopenia, elevated lactate dehydrogenase with schistocytes on peripheral smear examination, or low haptoglobin).

A total of 21 (17.5%) patients presented with RCN during pregnancy, all in the postpartum state. Twenty patients (95.2%) showed microangiopathic hemolytic anemia consistent with HUS and 1 (4.8%) patient had biopsy-proven thrombotic microangiopathy. Low complement 3 or activation of an alternate complement pathway was seen in 9 of 15 patients in which it was done. At the end of 6 months, only 2 (9.5%) patients had partial recovery of renal functions, 5 (23.8%) patients died, and 14 remained (66.7%) on hemodialysis.

The clinical and laboratory features are highly suggestive of aHUS in more than three-fourths of cases with postpartum RCN. Investigations are needed to look for genetic abnormalities in the complement pathway.