[Prenatal detection of open neural tube defects in a mass screening program by determination of alpha-fetoprotein concentration in maternal serum].

A partially automatized ultramicroencymimmunoassay developed by the GDR and Cuba should be tested in a mass screening for the prenatal detection of open neural tube defects by measurement of maternal alphafetoprotein concentration (MS-AFP). In the screening program 24,271 pregnant women were included (Berlin/District of Schwerin). In 18,144 patients AFP-concentration in maternal serum was measured as a routine procedure in the care for all pregnant women of the district of Schwerin. The time of MS-AFP determination in this connection was limited from 15th to 18th completed gestational week. 1986 already in 84.9 per cent of all pregnant women of the district of Schwerin MS-AFP concentration could be measured in early pregnancy. The detective rate of open neural tube defects among 24,271 tested pregnant women was 86.1 per cent. AFP concentration was expressed in ng/ml and the "cut off" was set at 2.0 MOM. Infants born with open neural tube defects were reduced by 75 per cent under the conditions of MS-AFP screening. Better results are possible in connection with a progress in the qualification of the following diagnostic steps, if MS-AFP-levels are elevated. Not unexpected and unspecific MS-AFP-elevation was found in connection with twin pregnancies and a higher risk of abortion and the delivery of infants with very low birth-weight less than 1,500 g. A general MS-AFP-screening is recommended for prenatal detection of open neural tube defects all over the country.