Table 1 Characteristics of children aged 7–13 years

Age (years)^d

9.66 ± 1.29

10.68 ± 1.16^a

9.76 ± 1.24^b

10.33 ± 1.25^abc

21.249

< 0.001

Gender^e

1.500

0.682

 Boys

49.1(112/228)

42.1(45/107)

47.8(75/157)

46.8(66/141)

 Girls

50.9(116/228)

57.9(62/107)

52.2(82/157)

53.2(75/141)

Height (cm)^d

138.42 ± 9.81

144.04 ± 9.33^a

137.56 ± 8.96^b

142.44 ± 8.96^ac

15.624

< 0.001

Weight (kg)^d

33.36 ± 8.69

37.63 ± 8.97^a

32.27 ± 6.49^b

36.51 ± 7.85^ac

13.811

< 0.001

BMI (kg/m²)^d

17.17 ± 2.68

17.99 ± 3.14^a

16.93 ± 2.36^b

17.82 ± 2.50^ac

5.112

0.002

Birth weight (kg)^d

3.36 ± 0.59

3.35 ± 0.39

3.38 ± 0.53

3.35 ± 0.46

0.090

0.965

CUF (mg/L)^d

0.82 ± 0.30

0.98 ± 0.29^a

2.05 ± 0.58^ab

2.13 ± 0.59^ab

378.736

< 0.001

IQ scores^d

123.92 ± 12.50

119.76 ± 11.28^a

124.65 ± 10.88^b

123.04 ± 11.24^b

4.139

0.006

Maternal age of pregnancy (y)^d

26.72 ± 4.95

25.51 ± 3.80^a

25.30 ± 3.81^a

25.70 ± 4.16^a

3.637

0.013

Gestational weeks (w)^d

36.98 ± 4.71

36.97 ± 4.95

37.19 ± 3.86

38.01 ± 3.76

1.363

0.253

Paternal education level (y)^e

2.661

0.850

 Primary school or below

9.0(19/210)

7.0(7/100)

6.7(10/149)

9.2(12/131)

 Junior high school

69.0(145/210)

71.0(71/100)

74.5(111/149)

66.4(87/131)

 High school or above

21.9(46/210)

22.0(22/100)

18.8(28/149)

24.4(32/131)

Maternal education level (y)^e

8.583

0.198

 Primary school or below

18.0(37/206)

10.0(10/100)

12.7(19/150)

10.2(13/128)

 Junior high school

59.7(123/206)

73.0(73/100)

68.7(103/150)

68.0(87/128)

 High school or above

22.3(46/206)

17.0(17/100)

18.7(28/150)

21.9(28/128)

Birth mode^e

8.525

0.202

 Natural labour

64.5(140/217)

75.7(81/107)

63.5(99/156)

72.9(97/133)

 Cesarean delivery

35.0(76/217)

24.3(26/107)

35.3(55/156)

26.3(35/133)

 Rest

0.5(1/217)

1.3(2/156)

0.8(1/133)