Fetal prolactin levels and respiratory distress syndrome.

Prolactin levels were measured by radioimmunoassay in cord blood of infants between 28 and 40 weeks of gestation. Also infants, whose mothers received betamethasone prior to delivery, were examined. Between 33 and 36 weeks, the mean plasma cord prolactin levels in infants who developed RDS were significantly lower than HPRL levels in those infants who did not develop RDS. These findings suggest that betamethasone did not alter HPRL levels and point out the possibility of a role of prolactin in fetal lung maturation.