We assessed cord prealbumin concentrations in 214 appropriate for gestational age newborn infants, 21 small for gestational age infants, and 27 large for gestational age infants to establish normal values and to assess the effect of intrauterine growth, prenatal steroids, and pulmonary maturity on prealbumin levels. Cord prealbumin values were significantly correlated with increasing gestational age (r=0.33; P<0.001) and birth weight (r=0.40, P<0.001) in the AGA neonates. Neonates born before 37 weeks gestation had significantly significantly lower levels than age-matched AGA controls (P<0.01), and LGA infants had significantly higher levels than age-matched AGA controls (P<0.001). In preterm infants, those with exposure to prenatal sterolds (betamethasone or premature rupture of membranes) had significantly higher prealbumin values than control infants of comparable age and weight (P<0.001). Infants without respiratory distress syndrome had higher levels than those of comparable age and weight with hyaline membrane disease (P<0.05). This study demonstrates that a correlation of gestational age and birth weight exists with cord prealbumin levels, and that the large variability at each gestational age may be accounted for in part by appropriateness of size for dates, prental steroid exposure, and pulmonary maturity.