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 |