Potential role of biochemical placentation markers - pregnancy associated plasma protein-A and human chorionic gonadotropin for early gestational diabetes screening - a pilot study

Objectives: Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications. The universal screening for GDM is usually performed between 24-28 weeks’ gestation. This often delays the diagnosis and could increase the risk of adverse pregnancy outcomes. Some of the biochemical placental markers — pregnancy associated plasma protein A (PAPP-A) and free-β human chorionic gonadotropin (hCG), probably could provide a diagnostic value for GDM. The aim of our study was to assess if PAPP-A and hCG values were different among pregnant women with and without GDM and respectively, to tested their place in the early GDM screening. Material and methods: We conducted a retrospective, case-control study by reviewing the clinical database records of 662 pregnant women. The analysis includes the data for a two-year period. The patients included in the observation were divided into two groups — GDM group (n = 412) and Euglycemic group (n = 250). Early screening for GDМ between 9–12 weeks’ gestation was performed in 173 of the women in the interventional group due to: registered fasting plasma glucose (FPG) above 5.1 mmol/L, obesity, macrosomia in previous pregnancies or family history for diabetes mellitus. The remaining 239 women underwent universal screening at 24–28 weeks’ gestation. Mean serum levels of PAPP-A, hCG, FPG, and body mass index (BMI) were measured between 10–13 gestational weeks. Serum levels of PAPP-A and hCG are presented as multiples of the normal median (MoM), adjusted by maternal baseline characteristics and demographics. Results: In patients who developed GDM during pregnancy, compared with the control group, we have found significantly lower MoM values of PAPP-A (p < 0.0001), higher levels of FPG (р < 0.0001) and higher BMI (р < 0.0001). Median hCG MoM was similar in both group of pregnant women. Conclusion: Our findings suggest that low-normal to low reference range values of PAPP-A might be associated with higher risk for GDM. PAAP-A levels can be used as an additional factor to recommend early screening for GDM.