Plasma renin activity and its postnatal development in preterm infants. Preliminary report.

Immunoassayable plasma renin activity (PRA) was measured in 16 healthy preterm infants of different gestational ages. A total of 52 measurements have been performed between the second week of life and the date of the expected term. PRA was found markedly increased in preterm infants and a highly significative negative correlation with postmenstrual age was proved.