Table 1.
Univariate and Multivariate Analysis of Association between Risk Factors and Neural Tube Defects
| Risk factors |
Case
n (%) |
Control
n (%) |
P value | Logistic regression | |
|---|---|---|---|---|---|
| OR (95% CI) | P value | ||||
| Sex | |||||
| Male | 37 (40.7) | 101 (48.3) | - | ||
| Female | 54 (59.3) | 108 (51.7) | 0.22 | ||
| Maternal age (yr) | |||||
| <20 | 7 (7.7) | 13 (6.2) | - | - | |
| 20-35 | 80 (87.9) | 165 (78.9) | 0.8 | 0.94 | |
| >35 | 4 (4.4) | 31 (14.8) | 0.04 | 0.059 | |
| Gravidity | |||||
| 1 | 46 (50.5) | 105 (50.2) | - | - | |
| 2 | 22 (24.2) | 76 (36.4) | 0.17 | 0.3 | |
| 3 | 12 (13.2) | 15 (7.2) | 0.16 | 0.2 | |
| >3 | 11 (12.1) | 13 (6.2) | 0.14 | 0.96 | |
| History of abortion | |||||
| No | 74 (81.3) | 199 (95.2) | - | 1 | - |
| Yes | 17 (18.7) | 10 (4.8) | <0.001 | 4.9 (1.9-12.8) | 0.001 |
| GDM | |||||
| No | 82 (90.1) | 196 (93.8) | - | ||
| Yes | 9 (9.9) | 13 (6.2) | 0.26 | ||
| Folic acid use | |||||
| No | 58 (63.7) | 131 (62.7) | - | ||
| Yes | 33 (36.3) | 78 (37.3) | 0.86 | ||
| Familial marriage | |||||
| No | 65 (71.4) | 169 (80.9) | - | - | |
| Yes | 26 (28.6) | 40 (19.1) | 0.07 | 0.4 | |
| BMI groups | |||||
| Underweight | 6 (6.6) | 11 (5.3) | - | - | |
| Normal | 45 (49.5) | 178 (85.2) | 0.15 | 0.2 | |
| Overweight | 22 (24.2) | 13 (6.2) | 0.06 | 0.07 | |
| Obese | 18 (19.8) | 7 (3.3) | 0.02 | 5.4 (1.3-21.8) | 0.019 |
| Season of birth | |||||
| Spring | 28 (30.8) | 61 (29.2) | - | ||
| Summer | 22 (24.2) | 56 (26.8) | 0.65 | ||
| Autumn | 22 (24.2) | 41 (19.6) | 0.66 | ||
| Winter | 19 (20.9) | 51 (24.4) | 0.55 | ||
| Family history of NTDs | |||||
| No | 89 (97.8) | 204 (97.6) | - | ||
| Yes | 2 (2.2) | 5 (2.4) | 0.9 | ||
BMI, body mass index; OR, odds ratio; CI, confidence interval; NTDs, neural tube defects; GDM, gestational diabetes mellitus