Raised maternal serum alpha-fetoprotein levels not associated with fetal malformations. A case report.

A pregnant black woman was found to have extremely high serum alpha-fetoprotein (AFP) concentrations on several occasions between 18 and 28 weeks of gestation; the amniotic fluid total AFP level was borderline at 22 weeks, and the concanavalin-A non-reactive fraction was below normal. At this stage termination of pregnancy was considered, but qualitative acetylcholinesterase electrophoresis was negative and repeated echographic examinations revealed no fetal defect. The pregnancy was allowed to continue, and a normal premature female infant was delivered at 36 weeks. Possible explanations and the potentially serious implications of the results of laboratory tests in a case such as this are discussed.