First trimester biochemical markers in pregnancies developing gestational diabetes

Background: Gestational diabetes mellitus (GDM) is a significant public health concern that is associated with adverse maternal and neonatal outcomes. Recent research has underscored the importance of various biomarkers in predicting the onset of GDM, with a specific focus on pregnancy-associated plasma protein A (PAPP-A). Several studies designate that low maternal PAPP-A levels are associated with an elevated risk of developing GDM. Methods: We conducted a retrospective study on singleton pregnancies we investigate the correlation between the first trimester free β-hCG and PAPP-A concentrations and the subsequent development of gestational diabetes, explore their potential in screening for GDM and explore their potential in screening for SGA in pregnancies with and without GDM in an inner city obstetric population undergoing universal GDM screening. Results: Overall, 1,241 singleton pregnancies were included and we observed that PAPP-A levels were significantly lower in women with GDM. PAPPA had modest but significant prognostic ability for GDM, (AUC=0.56; 95% CI: 0.52 – 0.60; p=0.005; Figure 1) and the optimal cut-off value would be <1.14 (sensitivity=58.3%, specificity=54.7%, PPV= 23.9% and NPV= 84.4%). In women without diabetes greater MoM PAPPA conferred a lower probability by about 60% of having a neonate with low BW ≤ 5th centile (OR=0.40; 95% CI: 0.19 – 0.83; p=0.014). In non-diabetic pregnancies PAPPA had a significant prognostic ability for BW ≤ 5th percentile (AUC=0.64; 95% CI: 0.56 – 0.72; p=0.006; Figure 2). Discussion: The results of our study indicate the association of low PAPPA with subsequent development of GDM. Diagnostic accuracy analysis indicated, however, that it is unlikely to be useful as a sole predictor of GDM although it can potentially be of value in a multi-factorial predictive model to assess the risk for GDM.