Table 1.
The description of characteristics by CHD cases versus controls, (n, %)
| Simple CHD | Severe CHD | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Unmatched | Matched | Unmatched | Matched | |||||||||
| Cases (n = 262) | Controls (n = 262) | p | Cases (n = 187) | Controls (n = 187) | p | Cases (n = 262) | Controls (n = 262) | p | Cases (n = 186) | Controls (n = 186) | p | |
| Demographic and obstetric characteristics | ||||||||||||
| Maternal ethnic | ||||||||||||
| Han | 250, 95.4 | 255, 97.3 | .243 | 180, 96.3 | 180, 96.3 | 1.000 | 251, 95.8 | 255, 97.3 | .337 | 179, 96.2 | 181, 97.3 | .557 |
| Other | 12, 4.6 | 7, 2.7 | 7, 3.7 | 7, 3.7 | 11, 4.2 | 7, 2.7 | 7, 3.8 | 5, 2.7 | ||||
| Maternal age at delivery | ||||||||||||
| <35 years old | 240, 91.6 | 240, 91.6 | 1.000 | 172, 92.0 | 172, 92.0 | 1.000 | 233, 88.9 | 240, 91.6 | .302 | 171, 91.9 | 166, 89.2 | .375 |
| ≥35 years old | 22, 8.4 | 22, 8.4 | 15, 8.0 | 15, 8.0 | 29, 11.1 | 22, 8.4 | 15, 8.1 | 20, 10.8 | ||||
| Maternal education | ||||||||||||
| Middle school and below | 83, 31.7 | 58, 22.1 | .014 | 48, 25.7 | 51, 27.3 | .866 | 101, 38.5 | 58, 22.1 | <.001 | 65, 34.9 | 52, 28.0 | .294 |
| High school | 55, 21.0 | 48, 18.3 | 44, 23.5 | 40, 21.4 | 62, 23.7 | 48, 18.3 | 33, 17.7 | 41, 22.0 | ||||
| College and above | 124, 47.3 | 156, 59.5 | 95, 50.8 | 96, 51.3 | 99, 37.8 | 156, 59.5 | 88, 47.3 | 93, 50.0 | ||||
| Marital status | ||||||||||||
| Married | 258, 98.5 | 257, 98.1 | 1.000a | 184, 98.4 | 184, 98.4 | 1.000a | 253, 96.6 | 257, 98.1 | .279 | 182, 97.8 | 182, 97.8 | 1.000a |
| Unmarried/divorced/widowed | 4, 1.5 | 5, 1.9 | 3, 1.6 | 3, 1.6 | 9, 3.4 | 5, 1.9 | 4, 2.2 | 4, 2.2 | ||||
| Residence | ||||||||||||
| Urban | 110, 42.0 | 166, 63.4 | <.001 | 87, 46.5 | 95, 50.8 | .408 | 99, 37.8 | 166, 63.4 | <.001 | 86, 46.2 | 91, 48.9 | .604 |
| Suburban/rural | 152, 58.0 | 96, 36.6 | 100, 53.5 | 92, 49.2 | 163, 62.2 | 96, 36.6 | 100, 53.8 | 95, 51.1 | ||||
| Maternal prepregnancy obesity | ||||||||||||
| Yes | 6, 2.3 | 9, 3.4 | .432 | 6, 3.2 | 5, 2.7 | .760 | 17, 6.5 | 9, 3.4 | .108 | 4, 2.2 | 7, 3.8 | .359 |
| No | 256, 97.7 | 253, 96.6 | 181, 96.8 | 182, 97.3 | 245, 93.5 | 253, 96.6 | 182, 97.8 | 179, 96.2 | ||||
| Multiple births | ||||||||||||
| Yes | 15, 5.7 | 23, 8.8 | .178 | 13, 7.0 | 11, 5.9 | .673 | 29, 11.1 | 23, 8.8 | .381 | 15, 8.1 | 21, 11.3 | .293 |
| No | 247, 94.3 | 239, 91.2 | 174, 93.0 | 176, 94.1 | 233, 88.9 | 239, 91.2 | 171, 91.9 | 165, 88.7 | ||||
| Infant gender | ||||||||||||
| Male | 128, 48.8 | 168, 64.1 | <.001 | 98, 52.4 | 100, 53.5 | .836 | 160, 61.1 | 168, 64.1 | .470 | 126, 67.7 | 110, 59.1 | .085 |
| Female | 134, 51.1 | 94, 35.9 | 89, 47.6 | 87, 46.5 | 102, 38.9 | 94, 35.9 | 60, 32.3 | 76, 40.9 | ||||
| Family history of CHD | ||||||||||||
| Yes | 20, 7.6 | 6, 2.3 | .005 | 3, 1.6 | 6, 3.2 | .502a | 11, 4.2 | 6, 2.3 | .218 | 5, 2.7 | 6, 3.2 | .760 |
| No | 242, 92.4 | 256, 97.7 | 184, 98.4 | 181, 96.8 | 251, 95.8 | 256, 97.7 | 181, 97.3 | 180, 96.8 | ||||
| Maternal health indicators and behaviors | ||||||||||||
| Diabetes/hypertension | ||||||||||||
| Yes | 2, 0.8 | 7, 2.7 | .176a | 2, 1.1 | 1, 0.5 | 1.000a | 8, 3.1 | 7, 2.7 | .793 | 4, 2.2 | 5, 2.7 | 1.000a |
| No | 260, 99.2 | 255, 97.3 | 185, 98.9 | 186, 99.5 | 254, 96.9 | 255, 97.3 | 182, 97.8 | 181, 97.3 | ||||
| Folic acid supplementation | ||||||||||||
| Yes | 204, 77.9 | 222, 84.7 | .044 | 147, 78.6 | 152, 81.3 | .518 | 186, 71.0 | 222, 84.7 | <.001 | 142, 76.3 | 148, 79.6 | .453 |
| No | 58, 22.1 | 40, 15.3 | 40, 21.4 | 35, 18.7 | 76, 29.0 | 40, 15.3 | 44, 23.7 | 38, 20.4 | ||||
| Smoking/drinking | ||||||||||||
| Yes | 25, 9.5 | 26, 9.9 | .883 | 18, 9.6 | 19, 10.2 | .863 | 40, 15.3 | 26, 9.9 | .065 | 16, 8.6 | 22, 11.8 | .304 |
| No | 237, 90.5 | 236, 90.1 | 169, 90.4 | 168, 89.8 | 222, 84.7 | 236, 90.1 | 170, 91.4 | 164, 88.2 | ||||
| Sleep characteristics | ||||||||||||
| Short sleep duration | ||||||||||||
| Yes | 87, 33.2 | 55, 21.0 | .002 | 63, 33.7 | 35, 18.7 | .001 | 79, 30.2 | 55, 21.0 | .016 | 57, 30.6 | 40, 21.5 | .045 |
| No | 175, 66.8 | 207, 79.0 | 124, 66.3 | 152, 81.3 | 183, 69.8 | 207, 79.0 | 129, 69.4 | 146, 78.5 | ||||
| Poor sleep quality | ||||||||||||
| Yes | 22, 8.4 | 6, 2.3 | .002 | 17, 9.1 | 4, 2.1 | .004 | 14, 5.3 | 6, 2.3 | .068 | 10, 5.4 | 3, 1.6 | .048 |
| No | 240, 91.6 | 256, 97.7 | 170, 90.9 | 183,97.9 | 248, 94.7 | 256, 97.7 | 176, 94.6 | 183, 98.4 | ||||
| Poor sleep | ||||||||||||
| Yes | 94, 35.9 | 56, 21.4 | <.001 | 69, 36.9 | 36, 19.3 | <.001 | 83, 31.7 | 56, 21.4 | .008 | 60, 32.3 | 40, 21.5 | .019 |
| No | 168, 64.1 | 206, 78.6 | 118, 63.1 | 151, 80.7 | 179, 68.3 | 206, 78.6 | 126, 67.7 | 146, 78.5 | ||||
| Daytime nap | ||||||||||||
| Yes | 132, 50.4 | 163, 62.2 | .006 | 93, 49.7 | 115, 61.5 | .022 | 132, 50.4 | 163, 62.2 | .006 | 97, 52.2 | 113, 60.8 | .094 |
| No | 130, 49.6 | 99, 37.8 | 94, 50.3 | 72, 38.5 | 130, 49.6 | 99, 37.8 | 89, 47.8 | 73, 39.2 | ||||
CHD = congenital heart disease.
a
The Fisher's exact test was used; in the other cases, the Chi‐square test was applied.