Neonatal hypocalcaemic seizures unmasking asymptomatic maternal primary hyperparathyroidism

Hypocalcaemia is a common cause of neonatal seizures. Here, we present a breastfed neonate with smooth perinatal transition and no family history of seizures presenting at 3 weeks with recurrent multifocal clonic seizures. On evaluation, the neonate was found to have low iCa and total calcium. 25-hydroxy vitamin D (25(OH)D) level was low and intact parathyroid hormone (iPTH) was inappropriately normal. The maternal evaluation revealed high calcium and low phosphate levels. iPTH was very high and 25(OH)D was very low in the mother. Sestamibi scan showed a left inferior parathyroid adenoma in the mother. Maternal primary hyperparathyroidism causing hypercalcaemia can suppress parathyroid activity in the fetus, resulting in inappropriate parathyroid response to hypocalcaemia after birth causing recurrent hypocalcaemic seizures. So neonatal hypocalcaemic seizures need careful evaluation of the neonate and the mother at times and can help both mother and neonate.