Background Hyper ammonia is well described cause of postpartum coma. It can be a consequence of inherited enzyme defects in the urea cycle. Severe forms present in the neonatal period with symptoms ranging from lethargy, seizures or even coma. With milder enzyme deficiencies, onset can be later in life and ammonia accumulation occurs during periods of stress such as sepsis, surgery or any illness.

Case The case of a 34-year-old lady is presented who had an emergency caesarean section for failed trial of labour (dizygotic twins) at 37 weeks. This was complicated by postpartum haemorrhage, thrombocytopaenia and abnormal coagulation which was treated with fresh frozen plasma, platelets and bloods transfusion. Over the course of day 3 postpartum, her GCS dropped to 3. MRI brain was completely normal. EEG showed an encephalopathic picture. Ammonia levels were found to be more than 450 μm/l. This was treated with dialysis, low protein, and high caloric diet and nitrogen scavengers.

Conclusion Urea cycle disorders should be considered in the differential diagnosis of acute mental status changes in the postpartum period.