ALPHA-FETOPROTEIN IN WOMEN DURING PREGNANCY AND IN THE NEONATE RING INTRAPARTUM

To evaluate alpha-fetoprotein (AFP) levels in women during pregnancy and in the neonate, 256 singleton pregnancies without medical, gynecologic, obstetric, or neonatal complications were studied. Sera for measuring maternal AFP (MAFP) levels were taken in midtrimester (16 to 18 weeks), third trimester (32 to 34 weeks),and during intrapartum (38 to 41 weeks). For measuring umbilical arterial AFP (UAAFP) and umbilical venous AFP (UVAFP) levels, sera of newborn were taken from the umbilical cord at delivery. AFP levels were measured by radioimmunoassay. Our results show that the MAFP levels at third trimester were higher than during intrapartum or midtrimester. Birthweights correlated well with MAFP levels in midtrimester. However, they did not significantly correlate with the MAFP levels at third trimester or intrapartum, nor with UAAFP or UVAFP levels. UAAFP levels were not significantly different from UVAFP levels. Intrapartum MAFP correlated well with UAAFP but not with UVAFP, birthweight, or parity. The concentration gradient between fetal and maternal serum during intrapartum is approximately 750:1. We conclude that MAFP levels in midtrimester can reflect birthweight. The data of normal AFP gradient may also be useful for diagnosing intrapartum fetomaternal hemorrhage.