Pregnancy-associated renal thrombotic microangiopathy is a rare condition with poor maternal outcome. Pregnancy may trigger atypical hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. The article describes the clinical case of a 37-year-old woman who developed acute renal failure following complicated delivery. A turn-based differential diagnosis of atypical hemolytic uremic syndrome was performed. Unwarranted discontinuation of the targeted therapy with Eculisumab led to the development of chronic renal failure. Pregnancy-associated atypical hemolytic uremic syndrome is a life-threatening condition rarely seen in pregnancy making its early recognition difficult. As thrombotic microangiopathies require urgent treatment, plasmapheresis should be started as soon as they are suspected, followed by Eculisumab after the confirmation of the diagnosis of atypical hemolytic uremic syndrome. This may contribute to reducing maternal morbidity and mortality rates.