Table 4. Adjusted OR values between NVP and different subtypes of NTDs stratified by intake of folic acid supplements.
| Anencephaly | Spina bifida | Encephalocele | ||||
|---|---|---|---|---|---|---|
| Factor | OR (95%CI) | P | OR (95%CI) | P | OR (95%CI) | P |
| NVP# | ||||||
| Light | 1.000 | 1.000 | 1.000 | |||
| Moderate | 1.744(0.951,3.199) | 0.072 | 1.561(0.898,2.711) | 0.114 | 2.438(0.666,8.922) | 0.093 |
| Severe | 3.738(1.158,12.073) | 0.028 | 1.313(0.615,2.805) | 0.482 | 6.087(0.741,50.035) | 0.197 |
| Intake of folic acid supplements# | ||||||
| Light NVP | 1.000 | 1.000 | 1.000 | |||
| Moderate NVP | 0.842(0.330,2.146) | 0.718 | 1.099(0.438,2.760) | 0.841 | 0.762(0.092,6.375) | 0.998 |
| Severe NVP | 1.182(0.149,9.356) | 0.874 | 1.941(0.558,6.744) | 0.297 | - | - |
| Non-intake of folic acid supplements# | ||||||
| Light NVP | 1.000 | 1.000 | 1.000 | |||
| Moderate NVP | 3.148(1.340,7.398) | 0.009 | 2.003(0.971,4.129) | 0.060 | 3.824(0.761,19.222) | 0.104 |
| Severe NVP | 6.724(1.519,29.758) | 0.012 | 1.137(0.447,2.896) | 0.787 | 5.606(0.443,70.882) | 0.183 |
*:Adjusted OR and 95%CI were calculated by adjusting the potential confounders, including age, occupation, education, annual income, BMI, passive smoking, exposure to pesticide, chronic disease, and intake of folic acid supplements.
#: The conditional logistic regression model was used to calculate the parameters.