Biochemical screening second trimester pregnancy

In the second trimester of pregnancy it is usual to test the levels of alpha fetoprotein (AFP), beta-hCG and estriol (E3). To do this, a blood test is performed on the mother.

For example, if the AFP values are higher than the reference values, this means that there is a multiple pregnancy. On the other hand, if the AFP concentration is low, it would be indicative of trisomy on chromosome 21 or 18.