Table 5 Subgroup analysis of effect modification of maternal characteristics on associations between FHR and LGA offspring

Age (years)

 < 35

7747

963 (12.4%)

2565

515 (20.1%)

1.70 (1.51, 1.92)

< 0.001

1.80 (1.58, 2.05)

< 0.001

 ≥ 35

996

203 (20.4%)

349

125 (35.8%)

3.70 (2.93, 4.66)

< 0.001

2.39 (1.85, 3.10)

< 0.001

BMI (kg/m²) ^a

 < 25

2191

112 (5.1%)

688

65 (9.4%)

1.81 (1.32, 2.50)

< 0.001

1.80 (1.30, 2.50)

< 0.001

 25–29

4726

611 (12.9%)

1605

353 (22.0%)

4.58 (3.66, 5.74)

< 0.001

4.17 (3.29, 5.27)

< 0.001

 ≥ 30

1741

432 (24.8%)

587

217 (37.0%)

9.34 (7.24, 12.06)

< 0.001

8.76 (6.68, 11.49)

< 0.001

Parity

 No child

5255

527 (10.0%)

1742

306 (17.6%)

1.82 (1.56, 2.13)

< 0.001

1.90 (1.61, 2.24)

< 0.001

 ≥ 1 child

3488

639 (18.3%)

1172

334 (28.5%)

3.36 (2.87, 3.93)

< 0.001

2.51 (2.09, 3.01)

< 0.001

Assisted reproduction

 No

8573

1136 (13.3%)

2814

610 (21.7%)

1.75 (1.56, 1.95)

< 0.001

1.82 (1.61, 2.05)

< 0.0001

 Yes

170

14 (8.2%)

100

30 (30.0%)

2.49 (1.61, 3.83)

< 0.001

1.91 (1.18, 3.10)

0.008

Pregnancy complications

 No

7199

883 (12.3%)

2338

470 (20.1%)

1.73 (1.53, 1.96)

< 0.001

1.80 (1.57, 2.06)

< 0.001

 GDM

681

166 (24.4%)

296

111 (37.5%)

4.02 (3.14, 5.16)

< 0.001

3.26 (2.46, 4.34)

< 0.001

 ICP

505

65 (12.9%)

213

48 (22.5%)

2.07 (1.48, 2.89)

< 0.001

1.91 (1.30, 2.81)

0.001

 PE

314

48 (15.3%)

92

17 (18.5%)

2.09 (1.20, 3.62)

0.009

1.09 (0.53, 2.24)

0.818

 PIH

202

36 (17.8%)

44

14 (31.8%)

3.08 (1.62, 5.85)

< 0.001

3.39 (1.60, 7.16)

0.001