Evaluation of four "kit" immunoassay methods for determination of alpha-fetoprotein in serum during pregnancy.

We evaluated four immunoassay methods for determination of alpha-fetoprotein in serum. All are commercially available in kit form in North American and we find them acceptable with respect to sensitivity, stability, precision, linearity, and analytical recovery. For the Dainabott method, the median values from 16 through 20 weeks of gestation are 34.4, 38.1, 42.1, 51.4, and 66.3 micrograms/L for each week, respectively. Corresponding values for the Amersham method are 27.9, 31.4, 34.9, 38.2, and 54.0 micrograms/L, respectively. For the Behring-RIA method they are 33.4, 37.4, 39.4, 49.9, and 66.3 micrograms/L, respectively. Results for four cases of confirmed neural tube defects are presented.