Blood sampling for measuring serum copeptin was at the early stage of pregnancy (GA: 8–2 weeks) in two studies [22, 23], at GDM screening (GA: 24–32 weeks) in six studies [18–21, 24, 25], and at or after delivery (GA: 37–39 weeks) in another two studies [16, 17]. This evidence concerns the gene AVP and gestational diabetes.