Table 1.
Selected demographic, lifestyle, and occupational exposure characteristics of mothers of infants with simple, isolated congenital heart defects and control infants, National Birth Defects Prevention Study, 1997–2002
| Congenital heart defect cases (n=2047) | Controls (n=2951) | P-Value* | |||
|---|---|---|---|---|---|
| N | % | N | % | ||
|
|
|||||
| Maternal age at delivery (years) | |||||
| <20 | 150 | 7.3 | 241 | 8.2 | 0.25 |
| 20–24 | 446 | 21.8 | 637 | 21.6 | |
| 25–29 | 543 | 26.5 | 787 | 26.7 | |
| 30–34 | 570 | 27.8 | 848 | 28.7 | |
| ≥35 | 338 | 16.5 | 438 | 14.8 | |
| Maternal education | |||||
| Less than high school | 219 | 10.7 | 295 | 10.0 | 0.08 |
| High school | 549 | 26.8 | 730 | 24.7 | |
| More than high school | 1276 | 62.3 | 1921 | 65.1 | |
| Missing | 3 | 0.1 | 5 | 0.2 | |
| Maternal race-ethnicity | |||||
| Non-Hispanic White | 1341 | 65.5 | 1910 | 64.7 | 0.48 |
| Non-Hispanic Black | 278 | 13.6 | 374 | 12.7 | |
| Hispanic | 330 | 16.1 | 520 | 17.6 | |
| Other | 97 | 4.7 | 140 | 4.7 | |
| Missing | 1 | 0.0 | 7 | 0.2 | |
| Maternal smoking during periconceptional† period | |||||
| Yes | 458 | 22.4 | 606 | 20.5 | 0.12 |
| No | 1589 | 77.6 | 2345 | 79.5 | |
| Missing | 0 | 0.0 | 0 | 0.0 | |
| Maternal folic acid intake during periconceptional† period | |||||
| Yes | 1792 | 87.5 | 2587 | 87.7 | 0.63 |
| No | 205 | 10.0 | 310 | 10.5 | |
| Missing | 50 | 2.4 | 54 | 1.8 | |
| Periconceptional† occupational exposure from expert consensus-based approach | |||||
| Any solvent | 96 | 4.7 | 110 | 3.7 | 0.09 |
| Chlorinated solvents | 88 | 4.3 | 101 | 3.4 | 0.11 |
| Stoddard solvent | 31 | 1.5 | 37 | 1.3 | 0.44 |
| Periconceptional† occupational exposure from literature-based approach | |||||
| Any solvent | 194 | 9.5 | 240 | 8.1 | 0.10 |
| Aromatic solvents | 50 | 2.4 | 61 | 2.1 | 0.35 |
| Benzene | 16 | 0.8 | 16 | 0.5 | 0.28 |
| Toluene | 45 | 2.2 | 59 | 2.0 | 0.59 |
| Xylene | 47 | 2.3 | 60 | 2.0 | 0.50 |
| Chlorinated solvents | 156 | 7.6 | 203 | 6.9 | 0.30 |
| Carbon tetrachloride | 5 | 0.2 | 8 | 0.3 | 0.87 |
| Chloroform | 58 | 2.8 | 83 | 2.8 | 0.91 |
| Methylene chloride | 137 | 6.7 | 177 | 6.0 | 0.30 |
| Perchloroethylene | 82 | 4.0 | 108 | 3.7 | 0.49 |
| Trichloroethane | 138 | 6.7 | 175 | 5.9 | 0.23 |
| Trichloroethylene | 69 | 3.4 | 94 | 3.2 | 0.67 |
| Stoddard solvent | 67 | 3.3 | 79 | 2.7 | 0.21 |
*
P-value for Chi-Square test of association
†
Periconceptional defined as one month before conception through the end of the first trimester.