[Applications of the quantitative determination of alpha-fetoprotein in obstetrics].

Mancini's technique of simple radial immunodiffusion was used in a study of the alpha-fetoprotein (AFP) content of the amniotic fluid (327 samples), the cord blood (100 samples) and the blood of the newborn infant (28 samples) in the days following birth. The tests for AFP were positive in 26 samples of amniotic fluid: 19 of them were from pregnancies of less than 25 weeks (the levels of AFP varied between 1 and 4.7 mg/100 ml) and 7 were from pregnancies in which grave fetal distress was followed by death of the fetus in utero (levels of AFP varied between 1.3 and 22 mg/100 ml). Fetal distress was connected with Rhesus incompatibility in 3 cases, with a toxaemic syndrome in one case, and was unexplained in the other cases. Analysis of AFP levels in the cord blood of newborn infants of gestational ages between 33 and 42 weeks did not show a close relation with gestational age because of large, individual differences. There was a better correlation with the birthweight of the infant. The fall in the serum level of AFP was followed in 17 newborn infants during the post-natal period. The decrease in the level of AFP was about 50 percent by the 5th day and 90 percent by the 9th day after birth.