FGF21 and gestational diabetes: Additionally, the association of FGF21 and GDM was assessed using logistic regression analysis by stratifying study subjects into quartiles for FGF21 levels (Q1 ≤ 27.83 pg/mL, Q2 28.00 to 45.82 pg/mL, Q3 46.81 to 83.87 pg/mL, Q4 ≥ 84.09 pg/mL).