General characteristic of pregnant women with or without adverse pregnancy/neonatal/growth outcomes.

*Low education level means illiteracy or basic education only, namely the Chinese nine-year compulsory education (elementary school education for 6 years and junior high school education for 3 years). Senior high school education and above was considered as “high level”.†Maternal basic disease: maternal disease existing before conception, including hypertension, cardiac disease, systematic lupus erythematosus and hyperthyreosis in this study.§Prior adverse pregnancy outcomes: including spontaneous abortion for twice or more, previous fetal, neonatal or infant death, congenital malformation, and growth retardation.General characteristic of pregnant women with or without adverse pregnancy/neonatal/growth outcomes.