Table 2.
Intake of iron in the diet and with supplements during pregnancy and risk of small for gestational age
| Cases n (%) | Controls n (%) | OR (95% CI) | aOR (95% CI) | |
|---|---|---|---|---|
| Diet iron, quintiles (mg/day) | ||||
| <15.9 | 115 (22.2) | 104 (20.1) | 1 “Reference” | 1 “Reference” |
| 15.9–17.7 | 120 (23.2) | 104 (20.1) | 1.04 [0.71, 1.51] | 1.04 [0.67, 1.59]a |
| 17.8–19.2 | 103 (19.9) | 103 (19.9) | 0.89 [0.62, 1.30] | 0.90 [0.59, 1.37] |
| 19.3–21.3 | 73 (14.5) | 104 (20.1) | 0.65 [0.43, 0.97] | 0.56 [0.35, 0.90] |
| >21.3 | 105 (20.3) | 103 (19.9) | 0.92 [0.63, 1.36] | 0.97 [0.62, 1.52] |
| Iron (supplement) | ||||
| No | 255 (49.2) | 210 (40.5) | 1 “Reference” | 1 “Reference” |
| Yes | 263 (50.8) | 308 (59.5) | 0.68 [0.53, 0.88] | 0.76 [0.55, 1.04]a |
| ≤40 mg/day | 117 (24.6) | 111 (23.1) | 0.82 [0.58, 1.16] | 0.80 [0.54, 1.17] |
| >40 mg/day | 103 (21.6) | 159 (33.1) | 0.55 [0.39, 0.77] | 0.64 [0.42, 0.99] |
| Unknownc | 43 (4.6) | 38 (3.3) | ||
| No anaemia and no iron supplement | 247 (47.7) | 195 (37.6) | 1 “Reference” | 1 “Reference” |
| Anaemia and no iron | 8 (9.7) | 15 (2.9) | 0.37 [0.14, 0.99] | 0.34 [0.12, 0.99]b |
| No anaemia and iron | 158 (30.5) | 171 (33.0) | 0.71 [0.53, 0.96] | 0.73 [0.50, 1.06]b |
| ≤40 mg/day | 87 (16.8) | 87 (16.8) | 0.77 [0.54, 1.10] | 0.73 [0.50, 1.06] |
| >40 mg/day | 71 (13.7) | 84 (16.2) | 0.65 [0.44, 0.95] | 0.64 [0.43, 0.97] |
| Anaemia and iron | 105 (20.3) | 137 (26.5) | 0.59 [0.42, 0.81] | 0.57 [0.40, 0.81]b |
Abbreviations: aOR, adjusted odd ratio; CI, confidence interval; OR, odd ratio.
a
Adjusted for pre‐eclampsia, smoking, body mass index, iron supplements, total food energy, previous preterm/low‐birthweight newborn, and anaemia during pregnancy.
b
Adjusted for pre‐eclampsia, smoking, body mass index, total food energy, and previous preterm/low‐birthweight newborn.
c
Women who did not remember the brand of the supplement.