Table 1 Characteristics of mothers with and without gestational diabetes mellitus

Age at enrollment (Years)

29.8 ± 3.8

31.3 ± 4.2

< 0.001

Ethnicity

0.72

 Han

613 (82.8)

127 (17.1)

 Others

172 (83.9)

33 (16.1)

Educational attainment

0.64

 Middle school or below

60 (8.1)

17 (8.3)

 High school

107 (14.5)

31 (15.1)

 College

507 (68.5)

133 (64.9)

 Graduate or above

66 (8.9)

24 (11.7)

Household income per year, CNY

0.83

  < 30,000

197 (26.6)

51 (24.9)

 30,000- < 50,000

191 (25.8)

57 (27.8)

 50,000- < 70,000

166 (22.4)

42 (20.5)

  ≥ 70,000

186 (25.1)

55 (26.8)

Parity

0.003

 1

585 (79.1)

142 (69.3)

  > 1

155 (21.0)

63 (30.7)

Gestational age (Weeks) ^a

38.9 ± 1.3

38.6 ± 1.2

< 0.001

Pre-pregnancy BMI category, kg/m²

< 0.001

  < 18.5

121 (16.4)

12 (5.9)

 18.5- < 24.0

451 (61.0)

120 (58.5)

  ≥ 24.0

168 (22.7)

73 (35.6)

Paternal BMI category, kg/m^{2 b}

0.27

  < 18.5

22 (3.1)

2 (1.0)

 18.5- < 24.0

274 (38.3)

74 (37.6)

  ≥ 24.0

419 (58.6)

121 (61.4)

Infant sex

0.41

 Male

356 (48.1)

92 (44.9)

 Female

384 (51.9)

113 (55.1)