GPT and gestational diabetes: A recent meta-analysis of eight studies reported that gamma-glutamyl transferase (GGT) was a significant and robust predictor of incident GDM in pregnant women [22], while the association between alanine aminotransferase (ALT) levels in early pregnancy and GDM risk was inconsistent [23–25] and studies on alkaline phosphatase (ALP) or aspartate aminotransferase (AST) were scarce [22].