First-trimester biochemical markers of placentation in screening for gestational diabetes mellitus

To investigate whether first-trimester biochemical markers of placentation, including pregnancy-associated plasma protein-A (PAPP-A) and placental growth factor (PLGF), are altered in women that subsequently develop gestational diabetes mellitus (GDM) and to examine their potential value in improving the performance of screening for GDM by maternal characteristics and medical history.

The study population of 31,225 singleton pregnancies, including 787 cases that developed GDM, was drawn from women undergoing routine prospective screening for pregnancy complications at 11-13 weeks' gestation. Maternal serum PAPP-A and PLGF were measured and the levels were expressed as multiples of the median (MoM) after adjustment for maternal characteristics and medical history. The performance of screening for GDM by maternal factors and MoM values of PAPP-A and PLGF was evaluated by receiver operating characteristic (ROC) curves.

In the GDM group, compared to the unaffected group, the median PAPP-A was reduced (0.949, 95% CI 0.913-0.987 MoM) (p=0.0009) and median PLGF was increased (1.053, 95% CI 1.023-1.083 MoM) (p=0.004). The performance of screening for GDM by maternal factors was not improved by the addition of PAPP-A and/or PLGF.

First trimester maternal serum PAPP-A and PLGF are not useful in screening for GDM.