Abnormal liver function diseases including viral hepatitis (hepatitis A, B, C, D, E virus, EB virus, cytomegalovirus, etc.), liver and gallstones, acute fatty liver during pregnancy, preeclampsia, gestational diabetes mellitus, autoimmune liver disease, drug-induced liver injury, and other medical complications were all excluded in ICP4 group, and maternal elevated serum ALT can not be explained by any other reason. The gene discussed is GPT; the disease is gestational diabetes.