Table 1 Demographic and clinical characteristics of mothers and infants (N = 370)

Mother

 Age (year)^a

30.0 (4.0)

 Educational level

   Postgraduate and above

35 (9.9)

   Bachelor’s degree

163 (46.3)

   High school and below

154 (43.8)

 Monthly household income (yuan)

   2000 ~ 

46 (15.5)

   5000 ~ 

159 (53.5)

   10,000 ~ 

92 (31.0)

 Pre-pregnancy weight (kg)^a

55.0 (10.0)

 Pre-pregnancy BMI (kg/m²)

   < 18.5

85 (23.5)

   18.5 ~ 23.9

222 (61.3)

   24 ~ 27.9

42 (11.6)

   ≥ 28

13 (3.6)

 Weight gain during pregnancy (kg)^a

18.5 (7.0)

 Gestational week (week)^a

39.1 (1.1)

Infant

 Gender

  Male

186 (50.8)

  Female

180 (49.2)

 Weight (kg)^a

3.4 (0.5)

 Length (cm)^a

50.0 (1.0)