Alpha-1 fetoprotein in cord serum correlated to gestational age.

Measurement of alpha1-fetoprotein by rocket immuno-electrophoresis in cord serum from a consecutive series of 422 newborn infants showed a negative correlation with gestational age. The coefficient of correlation was divided by 0.70 for girls and divided by 0.74 for boys. For a given alpha1-fetoprotein concentration in cord blood the confidence limits for prediction of gestational age for both sexes were calculated to +/- 24 days. It is concluded that determination of alpha1-fetoprotein in cord serum is of limited help in the evaluation of maturity.