Detectability and pattern of immunoglobulins in normal amniotic fluid throughout gestation.

Immunoglobulin (Ig) M, IgA, and IgD class and IgA, and IgA2 subclass levels were detected in normal amniotic fluid throughout gestation with a hemagglutination-inhibition assay: IgG was measured by single radial immunodiffusion. In 161 tested samples, IgA, IgA, IgA2, and IgG were measurable in all cases; IgM was measurable in 99.4 per cent and IgD, in 90.