Aldosterone cord levels in preterm newborn infants.

We measured umbilical cord aldosterone concentrations in 64 premature newborn infants. The median serum aldosterone level was 74.5 ng dl-1 (range 22-280 ng dl-1). Of the studied perinatal factors, only gestational age and birthweight presented a significant influence on the umbilical cord aldosterone levels. Newborn infants with a gestational age of over 34 weeks and a birthweight of over 2000 g had a significantly higher aldosterone cord level than those aged 34 weeks or younger and 2000 g or less in weight.