The effect of antenatal betamethasone on cord blood concentrations of retinol-binding protein, transthyretin, transferrin, retinol, and vitamin E

We assessed the effect of short-term (> 1 week) and prolonged (> 1 week) exposure to antenatal betamethasone on umbilical cord serum concentrations of retional-binding protein (serum t_1/2 - 12 h), transthyretin (t_1/2 - 2 days), transferrin (t_1/2 - 8 days), retinol (vitamin A), and vitamin E in appropriate-for-gestational-age preterm newborn infants of < 36 weeks’ gestation. A group of 30 infants whose mothers received a single course of betamethasone < 1 week prior to delivery had significantly elevated mean retional-binding protein and transthyretin but not transferrin concentrations when compared with a group of 30 gestational age-and birth weight-matched infants with no exposure to antenatal betamethasone. A group of eitht infants whose mothers received multiple (more than two) weekly course of betamethasone prior to delivery had significantly elevated mean serum concentrations of all three proteins when compared with eight gestational age-and weight-matched control infants with no betamethasone exposure. Serum retinol and vitamin E concentrations were measured in a group of 21 infants exposed to short-term prenatal betamethasone and were significantly greater than in a group of 21 control infants without steroid exposure. We conclude that antenatal steroids increase the umbilical cord serum concentrations of retional-binding protein, transthyretin, transferrin, retinol, and vitamin E. The effect on the various serum proteins is dependent on the duration of exposure to steroids.