Background: Neonatal illness may occasionally lead to the diagnosis of a yet undiagnosed maternal illness, such as neonatal heart block and maternal systemic lupus erythematosus or neonatal hypotonia and maternal
myotonic dystrophy. It is however very rare to diagnose a significant medical problem in the mother of an otherwise healthy newborn.
Case report: A 36-year-old woman with earlier episodes of hyperemesis requiring intravenous rehydration was admitted at 33 weeks of gestation in spontaneous labour. The newborn developed mild abdominal distension
and vomiting the age of 12 hours. Physical examination and urine output were normal and there was no haematuria or proteinuria. Serum urea and creatinine were elevated. Vomiting did not recur, feeds were resumed and the rest of her clinical course was uneventful. Serial blood biochemistry results showed progressive normalisation of serum creatinine and urea. The child’s mother soon developed recurrent vomiting few hours after birth and was found to be clinically dehydrated, oliguric but normotensive. Serum creatinine and urea were elevated. Following intravenous rehydration, urine output and serum biochemistry improved over the next few days.
Conclusions: Estimation of plasma creatinine and serum electrolytes is not indicated in the newborn soon after birth. However, abnormal results may serendipitously diagnose maternal renal dysfunction.

Keywords: Creatinine, Maternal-Fetal Exchange, Urea, Kidney Failure, newborn, Pregnancy