Table 1 Baseline Characteristics of Cases and Controls
|  | Control(N = 77) n(%) | Case(N = 53) n(%) | P value |
|---|---|---|---|
Maternal age (years) | Â | Â | 0.009 |
 <25 | 1(1.3) | 4(7.5) |  |
 25 ≤ Y<30 | 20(26.0) | 23(43.4) | |
 ≥ 30 | 56(72.4) | 26(49.1) | |
Maternal education level | Â | Â | 0.009 |
 Below the undergraduate level | 8(10.4) | 15(28.3) |  |
 College or higher | 69(89.6) | 38(71.7) | |
Paternal education level | Â | Â | 0.002 |
 Below the undergraduate level | 8(10.4) | 17(32.1) |  |
 College or higher | 69(89.6) | 36(67.9) | |
Residence | Â | Â | 0.043 |
 Urban | 40(51.9) | 18(34.0) |  |
 Rural | 37(48.1) | 35(66.0) | |
Parity | Â | Â | 0.719 |
 Primiparous | 47(61.0) | 34(64.2) |  |
 Multiparous | 30(39.0) | 19(35.8) | |
Cold/ Fever in early pregnancy | Â | Â | 0.183 |
 no | 44(57.1) | 24(42.3) |  |
 yes | 33(42.9) | 29(54.7) | |
Maternal passive smoking | Â | Â | 0.613 |
 no | 47(61.0) | 30(56.6) |  |
 yes | 30(39.0) | 23(43.4) | |
Maternal alcohol consumption | Â | Â | 0.651 |
 never/irregularly | 76(98.7) | 52(98.1) |  |
 regularly | 1(1.3) | 1(1.9) | |
Environmental pollutants around the residence* | Â | Â | 0.070 |
 no | 40(51.9) | 19(35.8) |  |
 yes | 37(48.1) | 34(64.2) | |
House Renovation | Â | Â | 0.551 |
 no | 56(72.7) | 41(77.4) |  |
 yes | 21(27.3) | 12(22.6) |