TTR and gestational diabetes: As for routine laboratory analysis parameters (Table 2), GDM cases had higher alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), alkaline phosphatase (ALP), prealbumin (PA), cholinesterase (CHE) but lower total bilirubin (TBIL), direct bilirubin (DBIL) in hepatic function tests (all P < 0.05).