RESUMO
BACKGROUND: Pre-delivery maternal electrolyte derangements may reflect themselves in the newborn, since placental homeostasis determines electrolyte equilibrium between mother and fetus. CASE PRESENTATION: A term newborn, transferred to our Neonatal Intensive Care Unit 1 h after birth for an apnoea episode, presented with initially left-sided, and subsequently generalized tonic-clonic seizures due to severe hyponatremia (119 mmol/L). Seizures rapidly ceased after electrolyte correction plus a phenobarbital bolus. Deep hyponatremia was also detected in the mother (123 mmol/L). CONCLUSIONS: As placental homeostasis determines electrolytes equilibrium between mother and fetus, obstetrics and neonatologists should be aware that any maternal dyselectrolytemia will reflect itself in the newborn; hence, it is fundamental to detect possible maternal electrolyte imbalances before delivery, in order to be prepared to timely correction of electrolyte derangements in the newborn.
