Abstract
Objective: To evaluate whether the maternal serum level of pregnancy-associated plasma protein-A (PAPP-A) in the first trimester can predict pregnancy complicated by low birth weight (LBW) and fetal growth restriction (FGR). Materials and Methods: This retrospective analysis enrolled 3,089 women with singleton pregnancy who underwent screening for Down syndrome in the first trimester of pregnancy and who delivered at Cathay General Hospital. They were divided into five groups according to the birth weight of their infants: three FGR groups of birth weight less than the 10 <sup>th</sup> , 5 <sup>th</sup> , and 3 <sup>rd</sup> centiles, a LBW group of birth weight less than 2,500 g, and a control group of all other women. Results: The mean multiples of median (MoM) values of PAPP-A were significantly lower in the LBW group (0.98) and the three FGR groups (< 10 <sup>th</sup> centile, 1.03; < 5 <sup>th</sup> centile, 0.96; and < 3 <sup>rd</sup> centile, 0.99) than in the control group (1.15). Women with PAPP-A less than 0.3 MoM, 0.5 MoM or in the 5 <sup>th</sup> centile (0.32 MoM) also had a significantly higher relative risk of pregnancy complicated by LBW and FGR, but the sensitivity of detection was low. The highest sensitivity using a cut-off at 0.5 MoM was 22.5%. Conclusion: Our study demonstrated that a low maternal serum PAPP-A level in the first trimester is associated with pregnancy complicated by LBW and FGR, but the sensitivity was low. As a single marker, PAPP-A is not sufficient to predict LBW and FGR.