Table 1.
Comparison of maternal characteristics in cases and controls a.
| Variables | Case (n = 620) | Control (n = 620) | Univariate analysisb |
|---|---|---|---|
| Age at this pregnancy (Years) | – | – | χ2 = 0.993; P = 0.319 |
| < 35 | 546(88.1%) | 557(89.8%) | – |
| ≥ 35 | 74(11.9%) | 63(10.2%) | |
| Residence | – | – | χ2 = 36.153; P < 0.001 |
| Rural | 444(71.6%) | 342(55.2%) | – |
| Urban | 176(28.4%) | 278(44.8%) | |
| BMI before pregnancy | – | – | χ2 = 18.353; P < 0.001 |
| < 18.5 | 112(18.1%) | 156(25.2%) | |
| 18.5–24.9 | 425(68.5%) | 382(61.6%) | |
| 24.9–29.9 | 62(10.0%) | 43(6.9%) | |
| ≥ 30.0 | 21(3.4%) | 39(6.3%) | |
| History of gestational diabetes mellitus(yes) | 63(10.2%) | 17(2.7%) | χ2 = 28.274; P < 0.001 |
| History of gestational hypertension(yes) | 43(6.9%) | 9(1.5%) | χ2 = 23.204; P < 0.001 |
| History of consanguineous marriage(yes) | 21(3.4%) | 3(0.5%) | χ2 = 13.766; P < 0.001 |
| Family history of congenital malformations(yes) | 36(5.8%) | 5(0.8%) | χ2 = 24.241; P < 0.001 |
| Cold before pregnancy(yes) | 121(19.5) | 72(11.6%) | χ2 = 14.734; P < 0.001 |
| Smoking before pregnancy(yes) | 36(5.8) | 13(2.1%) | χ2 = 11.240; P = 0.001 |
| Alcohol drinking before pregnancy(yes) | 81(13.1%) | 43(6.9%) | χ2 = 12.939; P < 0.001 |
| Folic acid consumption before or during pregnancy(yes) | 526(84.8%) | 577(93.1%) | χ2 = 21.344; P < 0.001 |
a Data presented as number (percentage) unless otherwise indicated;
b P < 0.05 was considered to indicate a statistically significant difference.