Inclusion Criteria:  Maternal age: 20-49 years Plan to have routine prenatal examinations and give birth in the research center Willing to cooperate with the hospital to follow up  Exclusion Criteria:  Have diseases that affect metabolic function or even threaten the life of the mother and fetus before pregnancy, such as diabetes, hypertension, heart disease, liver and kidney diseases, thyroid diseases, autoimmune diseases, malignant tumors, AIDS, etc. Fetus has a known deformity or genetic defects Incomplete clinical data