Maternal PAPP-A Levels at 11 - 13 Weeks of Gestation Predict Foetal and Neonatal Growth

Recent reports suggest that maternal serum levels of pregnancy-associated plasma protein A (PAPP-A) may predict perinatal outcome. PAPP-A is a syncytiotrophoblast derived protease for insulin-like growth factor binding protein (IGFBP4); its protease activity cleaves complexed growth factor binding protein increasing insulin-like growth factor I (IGF-I) bioavailability. The aim of our study was to evaluate the correlation between maternal PAPP-A serum levels and neonatal growth. We analysed 100 full term and preterm (30 - 36 weeks) small for gestational age (SGA) and adequate for gestational age (AGA) babies whose mothers had been tested for serum PAPP-A at 11 - 13 weeks of gestation. We found a significant positive correlation between maternal PAPP-A and neonatal weight, length, and head circumference at birth in both term and preterm infants. Low maternal PAPP-A serum levels (maternal PAPP-A < 0.5) were associated with small for gestational age neonates. A significant positive correlation was also evident between maternal PAPP-A and babies’ growth parameters at 6 months of age. Our results suggest that maternal levels of PAPP-A in early pregnancy affect growth during both foetal and early postnatal life.