First-trimester biomarkers are also influenced by the ethnic origin of the women (28, 29), however few studies have discussed first-trimester PAPP-A and free β-hCG levels related to the development of GDM in Chinese women (20, 23), and no study has investigated the association between first-trimester PLGF level and GDM in a Chinese population. The gene discussed is PAPPA; the disease is gestational diabetes.