Pregnancy-associated plasma protein-A

Pregnancy-associated plasma protein-A (PAPP-A) is a protein found in the maternal circulation and is produced by the placenta. The PAPP-A gene has been assigned to human chromosome 9q33.1 and contains 22 exons . PAPP-A values tend to rise exponentially during pregnancy and the reference range depends on the stage of gestation. The common practice is to use the unit multiple of median (MoM) as a gestational age-dependent expression of PAPP-A concentration.

Low maternal serum PAPP-A levels in the first trimester have been associated with a wide range of fetal pathology and pregnancy-related complications :

• aneuploidy (including Down syndrome)
• miscarriage
• pregnancy-induced hypertension
• intrauterine growth restriction
• gestational diabetes mellitus