Variables
Birthweight was collected by medical records. Fetal macrosomia was
defined as birthweight ≥4000 g. Maternal age was defined at the time of
preconception examinations. Maternal age was either as continuous or as
categorical variable. According to the result of association between
maternal age and macrosomia by cubic restricted splines (as shown in
Figure 1a), above 30 years old was regarded as “advanced maternal
age”. Hyperglycemia was defined as FPG levels > 5.6mmol/L,
with no self-reported diabetes mellitus.