Tests performed on serum are further categorized by the reason for performing the test: maternal serum, adult tumor marker, and pediatric tumor marker.

Maternal and paternal platelet antigen phenotyping and screening of the maternal serum for anti-platelet antibodies can be performed.

The triple test measures the following three levels in the maternal serum:

One indicator is low levels of unconjugated estriol in maternal serum, because this denotes adrenal hypoplasia.

Estetrol (E4), or 15α-hydroxyestriol, is an estrogen steroid hormone, found in detectable levels in maternal serum at around week 20.

Measurement of fetal proteins in maternal serum is a part of standard prenatal screening for fetal aneuploidy and neural tube defects.

The level of hCG in the blood is often used as part of a screening for birth defects in a maternal serum triple or quadruple screening test.

The level of AFP in the blood is used in a maternal serum triple or quadruple screening test.

Normally, a low level of these glycoproteins is detected in the maternal serum during the early stages of pregnancy.

For pregnant women, the level of estriol in the blood is used in a maternal serum triple or quadruple screening test.