Alpha-1 fetoprotein in pregnancy.
Experience with counterimmunoelectrophoresis (CIEP) for rapid screening of alpha fetoprotein (AFP) in pregnancy is presented. The CIEP method used detected as little as 250 ng of AFP per ml of serum. 2 groups were studied: Group 1 consisted of sera from 298 pregnant patients taken prior to term, and Group 2 was 83 paired maternal and cord sera obtained at parturition. In 3/83 cases in Group 2, maternal serum contained AFP greater than 250 ng at term (800, 600, and 800 ng). Presence of AFP in maternal sera of 2/3 of these cases was caused by admixture of fetal and maternal blood during the parturition process, as reported during Rh sensitization. In the 3rd case, a low concentration of AFP in cord serum indicated a different, but unknwon, cause for maternal AFP presence. The remaining 80 sera had AFP values below 250 ng. AFP concentration in 298 maternal sera obtained at various stages of pregnancy (Group 1) showed elevated (greater than 250 ng) AFP levels in 7 cases, all of which were associated with a dead fetus either before or at term. Anti-AFP was not detected in any of the maternal sera tested.