Plasma levels of catecholamine metabolites in the newborn period.

Plasma levels of homovanillic acid (HVA) and vanillylmandelic acid (VMA) were measured mass fragmentographically in 37 healthy preterm infants and 62 healthy infants born at term during the postnatal period. HVA and VMA levels increased after birth and declined steadily afterwards. Infants with various clinical problems showed marked elevations of HVA and VMA during episodes of clinical deterioration. The results indicate a readily functioning sympathoadrenal system in newborns.