Papp-A, Serum

PAPP-A, Serum

What it is

The PAPP-A (Pregnancy-Associated Plasma Protein-A) Serum test measures the level of PAPP-A, a protein produced by the placenta during pregnancy. It is an important component of the first-trimester screening for chromosomal abnormalities such as Down syndrome (trisomy 21) and Edwards syndrome (trisomy 18). Low levels of PAPP-A in maternal blood may also indicate risks of pregnancy complications like preeclampsia, intrauterine growth restriction (IUGR), or preterm delivery.

Uses

This test is primarily used as part of the first-trimester combined screening, along with free beta-hCG levels and an ultrasound for nuchal translucency measurement. It helps estimate the risk of chromosomal abnormalities in the fetus and provides early warning signs for pregnancy-related complications.

Symptoms That May Lead to the Test

The PAPP-A test is usually performed as a routine screening between 11–14 weeks of pregnancy, even in women without symptoms. However, it may be especially recommended for women with advanced maternal age, family history of chromosomal abnormalities, or previous pregnancy complications.

Abnormal Results

Low PAPP-A Levels: May indicate an increased risk of chromosomal abnormalities (such as Down syndrome or Edwards syndrome) or complications like preeclampsia, fetal growth restriction, or miscarriage. Further diagnostic testing may be required.

Normal PAPP-A Levels: Suggest a lower risk of chromosomal abnormalities and pregnancy complications, though results must be interpreted alongside ultrasound and other screening tests.

Risks

The test requires a routine maternal blood sample. Risks are minimal and may include mild pain, bruising, or dizziness at the puncture site. Serious complications are extremely rare.