Correlation of first-trimester serum levels of pregnancy-associated plasma protein A with small-for-gestational-age neonates and preterm births

Abstract Objective To analyze the relationship between first-trimester levels of pregnancy-associated plasma protein A (PAPP-A) and small-for-gestational-age (SGA) neonates and preterm births, and to assess predictive utility for these events. Methods A prospective study was conducted among women undergoing first-trimester screening between January 1, 2012, and December 31, 2013, at two centers in Pune, India. Serum PAPP-A levels, pregnancy course, and outcome were assessed. Results Overall, 1474 women were included. An association was found between the lowest quintile of PAPP-A levels (< 0.4 multiples of median) for both SGA (< 10th centile; 20.9% of cases in this PAPP-A quintile) and preterm birth (< 37 weeks; 15.8%). Women in the lowest quintile of PAPP-A concentration had a significantly increased risk of SGA (< 10th centile) than did those with higher concentrations (adjusted odds ratio 2.92, 95% confidence interval 2.00–4.27). Their risk of preterm birth (< 37 weeks) was also increased (adjusted odds ratio 1.84, 95% confidence interval 1.25–2.72). The predictive sensitivities of the lowest quintile of PAPP-A were 35.85% for SGA (< 10th centile) and 27.92% for preterm birth (< 37 weeks). Conclusion Low levels of PAPP-A were associated with SGA and preterm births; however, poor predictive sensitivity could restrict clinical utility of this marker when used alone.