Measurement of α-FP levels in the amniotic fluid

Elevated levels of alpha-fetoprotein-aFP, which is measured in an amniotic fluid sample, may indicate the presence of neural tube defects, such as spina bifida and anencephaly. The test may be performed up until the 25^th week of gestation; after this week it is not possible to evaluate the levels of alpha-fetoprotein.