Table 3.
Intake of iron during pregnancy and risk of gestational diabetes mellitus in the control group
| Total | Gestational diabetes mellitus n (%) | OR (95% CI) | aORa (95% CI) | |
|---|---|---|---|---|
| All control women | ||||
| Dietary iron, quintiles (mg/day) | ||||
| <15.9 | 104 | 4 (3.85) | 1 “Reference” | 1 “Reference” |
| 15.9–17.7 | 104 | 8 (7.69) | 2.08 [0.61, 7.14] | 2.08 [0.61, 7.37] |
| 17.8–19.2 | 103 | 3 (2.91) | 0.75 [0.16, 3.44] | 0.72 [0.15, 3.40] |
| 19.3–21.3 | 104 | 3 (2.88) | 0.74 [0.16, 3.40] | 0.79 [0.17, 3.68] |
| >21.3 | 103 | 10 (9.71) | 2.69 [0.81, 8.87] | 2.71 [0.80, 9.14] |
| P for trend | .036 | .040 | ||
| Iron (supplement) | ||||
| No | 210 | 8 (3.81) | 1 “Reference” | 1 “Reference” |
| Yes: Timing | ||||
| Early (<12 week) | 87 | 1 (1.15) | 0.29 [0.04, 2.38] | 0.38 [0.04, 3.19] |
| Late | 191 | 18 (9.42) | 2.38 [1.01, 5.55] | 3.40 [1.34, 8.58] |
| Yes: dose | ||||
| ≤40 mg/day | 111 | 4 (3.60) | 0.94 [0.28, 3.21] | 1.35 [0.37, 4.89] |
| >40 mg/day | 159 | 15 (9.43) | 2.63 [1.09, 6.37] | 3.53 [1.37, 9.05] |
| Anaemic women | ||||
| Iron (supplement) | ||||
| No | 15 | 1 (1.67) | 1 “Reference” | 1 “Reference” |
| Yes | ||||
| ≤40 mg/day | 24 | 2 (8.33) | 1.27 [0.11, 15.38] | 1 [0.72, 13.70] |
| >40 mg/day | 94 | 7 (7.45) | 1.13 [0.13, 9.87] | 0.98 [0.10, 9.23] |
| Nonanaemic women | ||||
| Iron (supplement) | ||||
| No | 195 | 7 (3.59) | 1 “Reference” | 1 “Reference” |
| Yes | ||||
| ≤40 mg/day | 87 | 2 (2.30) | 0.63 [0.13, 3.11] | 1.08 [0.20, 5.81] |
| >40 mg/day | 65 | 8 (12.31) | 3.77 [1.31, 10.85] | 6.32 [1.97, 20.23] |
Abbreviations: aOR, adjusted odd ratio; CI, confidence interval; OR, odd ratio.
a
Adjusted for total food energy, body mass index, and education level.