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

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.