Abstract

In 1983 a total of 1285 sera from pregnant women were analysed for alpha fetoprotein aiming to detect fetal neural tube defects. After elimination of sera with unknown or incorrect gestational age 1254 sera could be evaluated. Clinical post-partum results were reported in 71% of the cases. Of 31 pregnancies with a serum AFP-concentration higher than the internationally accepted 97 percentile in 20 cases (65%) a defect or other clinical condition was found, such as missed abortion, intrauterine fetal death and feto-maternal transfusions. Tow open neural tube defects and one case of gastroschisis yielded elevated AFP-levels. The sensitivity of the AFP-determination for the detection of open fetal neural tube defects turned out to be 100% with a positive predictive value of 6.5%. If all other defects and conditions yielding AFP-elevation were taken into account the sensitivity was 21% with a positive predictive value of 64.5%.