Table 5 Subgroup analysis of modified effect of BMI on associations between IMH and LGA neonates

Age < 35 years

Normal weight

2101

131 (6.2%)

22

4 (18.2%)

3.34 (1.11, 10.02)

0.031

3.59 (1.17, 11.07)

0.026

Overweight

4566

649 (14.2%)

251

28 (11.2%)

1.89 (1.23, 2.91)

0.004

1.96 (1.26, 3.05)

< 0.001

Obese

1581

411 (26.0%)

153

51 (33.3%)

7.52 (5.14, 10.99)

< 0.001

0.013

7.78 (5.19, 11.66)

< 0.001

0.015

Age ≥ 35 years

Normal weight

174

16 (9.2%)

5

1 (20.0%)

2.47 (0.26, 23.44)

0.431

1.72 (0.16, 19.05)

0.658

Overweight

613

145 (23.7%)

54

10 (18.5%)

2.24 (0.95, 5.29)

0.065

2.66 (1.09, 6.45)

0.031

Obese

278

101 (36.3%)

34

13 (38.2%)

6.11 (2.58, 14.47)

< 0.001

0.547

7.60 (3.04, 19.04)

< 0.001

0.661

Primipara

Normal weight

1513

70 (4.6%)

16

1 (6.2%)

1.37 (0.18, 10.55)

0.760

1.51 (0.19, 11.77)

0.694

Overweight

3045

353 (11.6%)

188

22 (11.7%)

2.73 (1.65, 4.53)

< 0.001

2.74 (1.63, 4.59)

< 0.001

Obese

999

239 (23.9%)

103

29 (28.2%)

8.08 (4.94, 13.21)

< 0.001

0.801

7.50 (4.46, 12.62)

< 0.001

0.877

Multipara

Normal weight

762

77 (10.1%)

11

4 (36.4%)

5.08 (1.46, 17.76)

0.011

4.11 (1.12, 15.12)

0.033

Overweight

2134

441 (20.7%)

117

16 (13.7%)

1.41 (0.79, 2.51)

0.244

1.29 (0.71, 2.32)

0.405

Obese

860

273 (31.7%)

84

35 (41.7%)

6.35 (3.88, 10.41)

< 0.001

0.002

6.45 (3.83, 10.88)

< 0.001

0.003

NPC

Normal weight

1952

123 (6.3%)

23

5 (21.7%)

4.13 (1.51, 11.31)

0.006

3.97 (1.36, 11.63)

0.012

Overweight

4324

633 (14.6%)

248

29 (11.7%)

1.97 (1.28, 3.02)

0.002

1.98 (1.27, 3.07)

0.002

Obese

1387

345 (24.9%)

123

42 (34.1%)

7.71 (5.09, 11.68)

< 0.001

0.003

7.63 (4.93, 11.82)

< 0.001

0.006