Pregnancy-associated plasma protein A levels and neonatal complications in post-date pregnancies.

Objectives: To assess the association between serum pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotropin (free β-hCG) in the first trimester and perinatal complications in post-date pregnancies.

Methods: A total of 4948 women, who delivered after 40 gestational weeks, were included. Labour was not induced routinely until 42 weeks. Serum levels of PAPP-A and free β-hCG were determined at the first-trimester screening for Down syndrome. Neonatal complications were obtained from specific registration forms filled out by senior neonatologists.

Results: In post-date pregnancies, PAPP-A < 0.4 multiples of the median was associated with Apgar score of less than 7 at 5 min (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 hypoglycaemia (ORadj 3.4, 95% CI 1.8-6.4). In small for gestation (SGA) neonates, the risk of hypoglycaemia was further increased (OR 14.6, 95% CI 3.4-58.0). Similar analyses were made with free β-hCG, but no statistically significant associations were found.

Conclusions: Low first-trimester serum PAPP-A was associated with increased neonatal morbidity in post-date pregnancies, particularly in newborns with SGA. Thus, PAPP-A may qualify the timing of induction of labour in these pregnancies.