Table 1.
Maternal characteristics during pregnancy among infants with and without CHD.
| Characteristics | Controls | Cases | χ2 or fisher | p |
|---|---|---|---|---|
| Age | ||||
| <30 | 673(54.80) | 453(73.78) | 62.018 | <0.001 |
| ≥30 | 555(45.20) | 161(26.22) | ||
| Education | ||||
| <Junior school | 5(0.41) | 36(5.86) | 425.418 | <0.001 |
| Junior school | 104(8.47) | 168(27.36) | ||
| High school | 185(15.07) | 244(39.74) | ||
| >High school | 934(76.06) | 166(27.04) | ||
| Wealth index | ||||
| Poor | 238(19.38) | 163(26.55) | 15.321 | 0.001 |
| Moderate | 737(60.02) | 355(57.82) | ||
| Rich | 253(20.60) | 96(15.64) | ||
| Smoking | ||||
| No | 1224(99.67) | 607(98.86) | — | 0.030 |
| Yes | 4(0.33) | 7(1.14) | ||
| Drinking | ||||
| No | 1220(99.35) | 592(96.42) | 21.958 | <0.001 |
| Yes | 8(0.65) | 22(3.58) | ||
| Taking folic acid | ||||
| No | 151(12.30) | 113(18.40) | 12.436 | <0.001 |
| Yes | 1077(87.70) | 501(81.60) | ||
| Taking medicine | ||||
| No | 884(71.99) | 389(63.36) | 14.287 | <0.001 |
| Yes | 344(28.01) | 225(36.64) | ||
| Pregnancy reaction | ||||
| No | 789(64.25) | 378(61.56) | 1.273 | 0.259 |
| Yes | 439(35.75) | 236(38.44) | ||
| Abnormal prenatal examination | ||||
| No | 1135(92.43) | 495(80.62) | 56.037 | <0.001 |
| Yes | 93(7.57) | 119(19.38) | ||
| Negative life events | ||||
| No | 1089(88.68) | 512(83.39) | 10.085 | 0.002 |
| Yes | 139(11.32) | 102(16.61) | ||
| Chronic disease | ||||
| No | 956(77.85) | 495(80.62) | 1.877 | 0.171 |
| Yes | 272(22.15) | 119(19.38) | ||
| Natural abortion history | ||||
| No | 1144(93.16) | 563(91.69) | 1.295 | 0.255 |
| Yes | 84(6.84) | 51(8.31) | ||
| Family history of CHD | ||||
| No | 1212(98.70) | 594(96.74) | 8.160 | 0.004 |
| Yes | 16(1.30) | 20(3.26) | ||
| Baby gender | ||||
| Male | 647(52.69) | 341(55.54) | 1.337 | 0.248 |
| Female | 581(47.31) | 273(44.46) | ||