Serum HPL level in maternal vein, umbilical cord artery and vein in term and preterm birth.

The serum HPL level in maternal vein and the cord vein and artery in term (n = 34) and preterm (n = 74) birth was tested to classify the hormonal changes and the correlation between the maternal and fetal HPL values. It was found that between the 28th and the 40th weeks of gestation the maternal level tended to increase while in the cord vein and artery it decreased significantly in negative correlation with the weeks of pregnancy. The maternal serum HPL level was significantly higher than that of the cord vein and artery. Between the 28th and 40th week the value in the cord artery divided by the value in the cord vein multiplied by 100 tended to decrease. While the HPL concentration in maternal serum did not correlate with its level in the cord vein and artery the levels in the cord vein and artery were significantly correlated. The characteristic and independent change in the fetal serum HPL concentration raised the possibility of a change in the transport function of the placenta and of an autonomous fetal HPL metabolism.