Table 1 Demographic and birth characteristics of the study population according to maternal body mass index (BMI) status early in pregnancy

Familial characteristics

Maternal BMI (kg/m²)

17.84 [17.21, 18.16]

21.06 [19.95, 22.37]

26.43 [25.41, 27.54]

–

Maternal height (cm)

153.2 ± 5.6

151.5 ± 4.9

151.2 ± 5.6

0.034

Maternal weight (kg)

41.3 ± 3.0

48.8 ± 4.8

61.2 ± 5.9

< 0.0001

Maternal age at childbirth (years)

24.1 ± 3.9

26.4 ± 4.6

28.4 ± 4.3

< 0.0001

Maternal education ^a

Less than high school

39 (81.3%)

400 (90.7%)

45 (97.8%)

0.029

High school or greater

9 (18.8%)

41 (9.3%)

1 (2.2%)

Paternal education ^b

Less than high school

31 (64.6%)

360 (81.6%)

42 (89.4%)

0.007

High school or greater

17 (35.4%)

81 (18.4%)

5 (10.6%)

Area of residence ^c

Urban

51 (83.6%)

400 (78.1%)

41 (80.4%)

0.64

Rural

10 (16.4%)

112 (21.9%)

10 (19.6%)

Family income (baht per month) ^d

3300 [2000, 5000]

2400 [1500, 4000]

2700 [1800, 4000]

0.08

Offspring at birth

Sex

Female

32 (51.6%)

276 (53.8%)

30 (56.6%)

0.86

Male

30 (48.4%)

237 (46.2%)

23 (43.4%)

Birth weight (kg)

2.82 ± 0.56

2.98 ± 0.41

3.18 ± 0.38

< 0.0001

Birth length (cm)

48.5 ± 3.1

48.7 ± 4.3

49.8 ± 2.2

0.19

38.9 ± 2.0

39.2 ± 1.7

39.4 ± 1.4

0.08

Offspring at follow-up

Age (years)

20.6 [20.3, 21.0]

20.6 [20.3, 20.9]

20.6 [20.3, 20.9]

0.24

Current smoking

8 (12.9%)

57 (11.0%)

8 (15.1%)

0.55