Examinations
Examinations
Pregnancy-Associated Plasma Protein-A (PAPP-A) is a zinc-containing enzyme (metalloproteinase).
- During pregnancy, it is produced in large amounts by fibroblasts of the placental outer layer and decidual tissue.
- Found in high-molecular-weight protein fractions in maternal blood.
- Increases insulin-like growth factor (IGF) activity, promoting placental growth and development.
- Deactivates specific enzymes (trypsin, elastase, plasmin) and modulates the maternal immune response.
- Levels steadily rise throughout pregnancy and are not influenced by fetal sex or weight.
- Between 7–14 weeks, PAPP-A strongly correlates with estradiol levels due to rapid placental formation.
- After birth, PAPP-A levels rapidly decline within days.
- Avoid fatty foods 24 hours before the test.
- Avoid physical/emotional stress and smoking for 30 minutes before testing.
Screening for chromosomal abnormalities (e.g., Down syndrome, Edwards syndrome, Patau syndrome).
Predicting pregnancy outcomes, assessing risks of miscarriage or preterm birth.
First-trimester screening (recommended at 9–13 weeks), especially in high-risk pregnancies:
- Maternal age ≥ 35 years
- Previous pregnancy loss
- History of chromosomal abnormalities, Down syndrome, or congenital defects in past pregnancies
- Family history of genetic disorders
- Exposure to radiation, infections, or teratogenic medications
Causes of Increased PAPP-A Levels
Multiple pregnancy
Large fetus and increased placental mass
Low placental position (placenta previa)
Causes of Decreased PAPP-A Levels