Cord blood transforming growth factor alpha varies with gestation

Objective To test the hypotheses that transforming growth factor alpha (TGF alpha) is present in cord blood and that TGF alpha concentration is associ ated with gestational age. Methods Umbilical venous cord blood samples (n=79) were processed immediate ly after delivery. Each cord serum sample was analyzed for TGF alpha concen tration (pg/ml) by radioimmunoassay. Obstetric and neonatal clinical charac teristics were also collected. Prematurity was defined as a gestational age of <37 weeks. The relationship of TGF<alpha> concentration with clinical c haracteristics of the cohort was determined. Results TGF alpha was present in all cord blood samples tested. The TGF alp ha concentration in the samples varied significantly as a function of gesta tional age (p=0.0001). The mean ( SID) cord serum TGF alpha concentration w as 16.4 +/-5.9 pg/ml in infants of <37 weeks' gestation and 27.0<plus/minus >9.7 pg/ml in infants of greater than or equal to 37 weeks' gestation. A lo wer mean TGF alpha concentration was associated with low birth weight (p=0. 002), respiratory distress syndrome (p=0.004) and with infants whose mother s had received betamethasone for fetal lung maturity (p=0.004) and tocolyti c therapy (p=0.03); however, these differences were no longer significant a fter controlling for gestational age. Conclusions Cord blood TGF alpha concentration and gestational age were str ongly associated, independently of birth weight and ethnicity: infants of g reater than or equal to 37 weeks' gestation had significantly higher TGF al pha concentrations than those of <37 weeks.