Epidermal growth factor (EGF) concentrations in amniotic fluid and maternal urine during pregnancy

Epidermal growth factor (EGF) was measured in amniotic fluid and maternal urine from women undergoing amniocentesis for genetic studies (15-22 weeks' gestation, n = 36) and lung maturational studies (35-39 weeks' gestation, n = 20). Amniotic fluid EGF concentrations (mean +/- SD) were higher near term (87 +/- 71 pM) than mid-gestation (35 +/- 8 pM) (p less than 0.0001). Urinary EGF concentrations were higher near mid-gestation (53.9 +/- 30.8 micrograms EGF/g creatinine) than near term (33.4 +/- 14.1 micrograms EGF/g creatinine) (p less than 0.006). There was no correlation between individual amniotic fluid and urinary EGF concentrations. The amniotic fluid EGF concentrations correlated with gestational age. However, there was no relationship between EGF concentrations and pulmonary maturity studies or placental weight from the pregnancies studied near term. We conclude that the concentration of EGF in amniotic fluid increases towards term. The lack of correlation between amniotic fluid and maternal urinary EGF concentrations suggests that there probably is a different source of EGF in the two compartments and that EGF does not cross the placenta to any great extent.