Table 3.
Associations between folic acid supplement use and the risk of preeclampsia (N=1059), Urban China, 2010–2012
| Folic acid supplement use | Controls |
Preeclampsia
|
|
|---|---|---|---|
| Cases | ORa (95% CI) | ||
| Nonusers | 150 | 115 | 1 |
| Users | 556 | 238 | 0.61 (0.43, 0.87) |
| ≤12 weeks | 348 | 147 | 0.62 (0.43, 0.89) |
| >12 weeks | 208 | 91 | 0.60 (0.39, 0.92) |
| P for trend | 0.55 | ||
| Before conception and during pregnancy |
209 | 97 | 0.64 (0.42, 0.98) |
| ≤12 weeks | 47 | 22 | 0.72 (0.38, 1.37) |
| >12 weeks | 162 | 72 | 0.61 (0.39, 0.97) |
| P for trend | 0.84 | ||
| Before conception only | 27 | 14 | 0.80 (0.36, 1.77) |
| ≤4 weeks | 9 | 4 | 0.60 (0.16, 2.24) |
| >4 weeks | 18 | 10 | 0.93 (0.36, 2.37) |
| P for trend | 1.00 | ||
| During pregnancy only | 320 | 130 | 0.59 (0.41, 0.85) |
| ≤8 weeks | 147 | 78 | 0.76 (0.50, 1.16) |
| >8 weeks | 173 | 52 | 0.44 (0.50, 0.69) |
| P for trend | 0.007 | ||
Abbreviations: CI, confidence interval; OR, odds ratio.
a
Adjusted for maternal age, education level, parity, maternal diabetes, prepregnancy BMI, weight gain during pregnancy, family monthly income per capita, multiple birth, maternal employment during pregnancy, history of gestational hypertension and dietary folate intake