Cases | Controls | Crude OR (95% CI) | Adjusted OR* (95% CI) | |
Folic acid (days) | ||||
⩽60 | 90 | 252 | 1.05 (0.77 to 1.43) | 0.98 (0.72 to 1.34) |
61–120 | 41 | 104 | 1.16 (0.76 to 1.76) | 1.01 (0.66 to 1.54) |
>150 | 17 | 66 | 0.76 (0.41 to 1.35) | 0.79 (0.44 to 1.42) |
p for trend | 0.569 | 0.474 | ||
Iron (days) | ||||
⩽60 | 85 | 141 | 1.04 (0.64 to 1.72) | 0.96 (0.58 to 1.59) |
61–120 | 95 | 265 | 0.62 (0.39 to 1.00) | 0.54 (0.34 to 0.88) |
>120 | 99 | 450 | 0.38 (0.24 to 0.61) | 0.35 (0.22 to 0.56) |
p for trend | <0.001 | <0.001 |
NA, Not available; OR, odds ratio.
Crude and multiple risk factor-adjusted for (logistic regression) analyses.
*Adjusted for smoking, maternal education, maternal age, Kessner index, body mass index, obstetric diseases during pregnancy, gestational age, and weight gain during pregnancy.