Table 3 The associations of hemoglobin levels with the risks of gestational diabetes mellitus, pre-eclampsia, and preterm birth

GDM

< 110

92 (15.8)

0.884 (0.703,1.111)

0.913 (0.721, 1.155)

102.066

< 0.001

72 (13.6)

0.763 (0.591, 0.986)

0.880 (0.678, 1.144)

54.94

< 0.001

20 (35.7)

1.246 (0.712, 2.180)

1.178 (0.668, 2.078)

6.52

0.01

110–129

1641 (17.5)

1

1

1261 (15.4)

1

380 (30.8)

1

1

130–149

2493 (22.1)

1.343 (1.253, 1.440)

1.272 (1.182, 1.369)

1699 (19.1)

1.296 (1.196, 1.404)

1.274 (1.171, 1.386)

794 (33.2)

1.114(0.961, 1.292)

1.162(0.998, 1.354)

≥150

111 (33.8)

2.418 (1.912, 3.058)

2.063 (1.609, 2.645)

59 (26.2)

1.946 (1.437, 2.635)

1.844(1.344, 2.529)

52 (50.5)

2.286(1.525, 3.427)

2.333(1.537, 3.541)

Per-unit increment

1.019 (1.016, 1.023)

1.015 (1.011, 1.018)

1.016 (1.012, 1.020)

1.015(1.011, 1.020)

1.011(1.004, 1.018)

1.013(1.006, 1.021)

PE

< 110

8 (1.4)

1.304 (0.632, 2.694)

1.422 (0.686, 2.945)

17.626

0.001

7 (1.3)

1.489 (0.682, 3.251)

1.618(0.738, 3.543)

1.22

0.27

1 (1.8)

0.843(0.112, 6.329)

0.843(0.112, 6.345)

4.981

0.095

110–129

99 (1.1)

1

1

73 (0.9)

1

1

26 (2.1)

1

1

130–149

166 (1.5)

1.405 (1.094, 1.804)

1.303 (1.006, 1.689)

94 (1.1)

1.186 (0.873, 1.613)

1.148(0.833, 1.580)

72 (3.0)

1.440(0.914, 2.266)

1.455(0.918, 2.306)

≥ 150

11 (3.4)

3.259 (1.731, 6.137)

2.375 (1.203, 4.688)

5 (2.2)

2.519 (1.008, 6.296)

2.535(1.006, 6.390)

6 (5.8)

2.869(1.153, 7.138)

2.195(0.814, 5.919)

Per-unit increment

1.026 (1.013, 1.038)

1.020 (1.007, 1.033)

1.015 (0.999, 1.030)

1.013(0.997, 1.030)

1.027(1.006, 1.049)

1.025(1.003, 1.047)

Preterm birth

< 110

41 (7.0)

1.415 (1.017, 1.969)

1.408 (1.008, 1.967)

15.572

0.001

37 (7.0)

1.436 (1.014, 2.036)

1.419(0.998, 2.019)

19.31

< 0.001

4 (7.1)

1.239(0.436, 3.522)

1.198(0.413, 3.479)

0.10

0.75

110–129

479 (5.1)

1

1

407 (5.0)

1

1

72 (5.8)

1

1

130–149

499 (4.4)

0.863 (0.759, 0.981)

0.795 (0.695, 0.910)

359 (4.0)

0.803 (0.695, 0.929)

0.768(0.660, 0.894)

140 (5.9)

1.002(0.747, 1.342)

0.949(0.699, 1.289)

≥ 150

8 (2.4)

0.465 (0.229, 0.944)

0.375 (0.183, 0.768)

3 (1.3)

0.258 (0.082, 0.808)

0.233(0.074, 0.735)

5 (4.9)

0.822(0.324, 2.083)

0.612(0.234, 1.598)

Per-unit increment

0.990 (0.984, 0.996)

0.987 (0.980, 0.993)

0.984 (0.977, 0.991)

0.982(0.975, 0.989)

1.005(0.991, 1.020)

1.000(0.986, 1.015)