Background: Infants whose mothers had low serum pregnancy-associated plasma protein-A (PAPP-A) in the first trimester were observed to have intrauterine growth retardation. Aim: Suggesting that PAPP-A plays an important role in the availability and activity of insulin-like growth factors (IGFs), which affect growth, we aimed to investigate cord blood PAPP-A levels of infants with different birth lengths and weights. Study design and outcome measures: The study included 97 full-term, live-birth neonates. After birth, their lengths and weights were measured. Cord blood PAPP-A Levels were measured with an ultra sensitive enzyme-linked immunosorbent assay (ELISA). Results: There was a significant negative correlation between cord blood PAPP-A levels and birth weight (r=-0.23; P=0.023) and length (r=-0.24; P=0.016). Using the classification made according to their length, it was found that newborns with short Lengths had significantly higher mean PAPP-A levels than neonates with normal and tong lengths (P=0.022; P=0.002, respectively), whereas the difference between infants with normal lengths and infants with Long lengths was not found to be statistically significant (P > 0.05). On the other hand, there was a difference between the mean PAPP-A levels of the neonate groups classified according to weight; however, these differences were not statistically significant (P > 0.05). Conclusion: We concluded that increased cord blood PAPP-A levels were associated with birth length and weight decreases; however, PAPP-A levels affected birth length more than birth weight. (c) 2006 Elsevier Ireland Ltd. All rights reserved.