Objectives To assess the association between serum pregnancy-associated plasma protein A (PAPP-A) measured in the first trimester and perinatal complications in post-term pregnancies.
Methods A total of 4948 singleton pregnant women, who delivered after 40+ 0 gestational weeks, were included at Aarhus University Hospital between January 2005 and December 2007. Serum levels of PAPP-A were determined at the first-trimester screening for Down syndrome (GA 8+ 0 – 13+ 6). Labor was not induced routinely until 42+ 0 weeks of gestation. However, in women with diabetes mellitus, gestational diabetes, preeclampsia, hypertension, prelabor rupture of membranes, twin pregnancies, fetal growth restriction and intrahepatic cholestasis, labor were induced by 40 completed weeks or earlier and were not included in the study.
Results In post-term pregnancies first-trimester serum PAPP-A below 0.4 MoM was associated with small weight for gestation (< 5th centile)(ORadj 1.7, 95% CI 0.9–3.0), Apgar score of less than 7 at 5 minutes (ORadj 5.4, 95% CI 2.0–14.3), admission to the neonatal intensive care unit (ORadj 1.5, 95% CI 1.0–2.3), and newborn hypoglycemia (ORadj 3.4, 95% CI 1.8–6.4). In neonates with small weight for gestation the risk of hypoglycemia was increased considerably (OR 14.6, 95% CI 3.4–58.0).
Conclusions Low first trimester serum PAPP-A was associated with increased neonatal morbidity in post-term pregnancies, particularly in newborns with low birth weight. Thus, PAPP-A may qualify the timing of induction of labor in these pregnancies and low PAPP-A may indicate more closely follow-up when past 40 weeks of gestation.