Ultrasonography and alpha-fetoprotein determination for antenatal detection of neural tube defects.

We review our experience in the antenatal detection of neural tube defects in a collaborative study between the prenatal diagnostic program of the Section of Medical Genetics and the Ultrasound Laboratory at the West Virginia University. In West Virginia the incidence of neural tube defects is two to three times the national average. The patients were referred to the sonic laboratory for a variety of reasons, even though they had not been classified in the high risk category. Our data confirm the advantage of ultrasonography for screening of the population in the early stages of pregnancy. The study also confirmed the value of serum and amniotic fluid alpha-fetoprotein (AFP) determination in conjunction with ultrasonography, especially when there is a positive family history. The combination of modalities appears to be the best means at present for detection of these severe disorders. Screening the general population in the early stages of pregnancy by means of ultrasonography, a noninvasive technic, can help to review fetal maturity and placental localization, as well as to detect neural tube defects. High risk mothers can then be followed up by further evaluations using serum or amniotic fluid AFP studies.