TABLE 1.
Sociodemographic and birth characteristics of mothers of infants with (cases) and without (controls) congenital heart defects (CHDs), National Birth Defects Prevention Study, 1997–2011.
| Cases |
Controls |
||
|---|---|---|---|
| n = 11,704 n (%) | n = 11,636 n (%) | Chi-Square p value | |
| Infant sex | <0.001 | ||
| Male | 6281 (53.7) | 5932 (51.0) | |
| Female | 5413 (46.3) | 5694 (49.0) | |
| Body mass index | <0.001 | ||
| Underweight (<18.5 kg/m2) | 592 (5.3) | 591 (5.3) | |
| Normal (18.5–24.9 kg/m2) | 5500 (49.0) | 5983 (53.7) | |
| Overweight (25.0–29.9 kg/m2) | 2675 (23.9) | 2524 (22.6) | |
| Obese (30 kg/m2) | 2444 (21.8) | 2046 (18.4) | |
| Season of birth | 0.36 | ||
| Spring | 2838 (24.2) | 2882 (24.8) | |
| Summer | 3064 (26.2) | 3015 (25.9) | |
| Autumn | 3020 (25.8) | 2906 (25.0) | |
| Winter | 2782 (23.8) | 2833 (24.3) | |
| Maternal race/ethnicity | 0.18 | ||
| Non-Hispanic White | 6825 (58.3) | 6731 (57.9) | |
| Non-Hispanic Black | 1344 (11.5) | 1280 (11.0) | |
| Hispanic | 2744 (23.5) | 2858 (24.6) | |
| Other | 788 (6.7) | 761 (6.5) | |
| Annual household income | <0.001 | ||
| <$10,000 | 2072 (19.2) | 1980 (18.8) | |
| $10,000–$50,000 | 5079 (47.2) | 4714 (44.7) | |
| >$50,000 | 3619 (33.6) | 3860 (36.5) | |
| Maternal education (in years) | <0.001 | ||
| <12 | 1947 (17.0) | 1876 (16.5) | |
| 12 | 2925 (25.5) | 2685 (23.6) | |
| 13–15 | 2751 (24.0) | 2606 (22.9) | |
| ≥16 | 3850 (33.5) | 4200 (37.0) | |
| Maternal age (in years) | <0.001 | ||
| <20 | 1034 (8.8) | 1149 (9.9) | |
| 20–34 | 8823 (75.4) | 8836 (75.9) | |
| ≥35 | 1847 (15.8) | 1651 (14.2) | |
| Number of previous livebirths | 0.42 | ||
| 0 | 4676 (39.9) | 4609 (39.6) | |
| 1 | 3718 (31.8) | 3789 (32.6) | |
| >1 | 3310 (28.3) | 3238 (27.8) | |
| Maternal gestational diabetes during index pregnancy | <0.001 | ||
| No | 10,246 (94.0) | 10,727 (95.3) | |
| Yes | 656 (6.0) | 528 (4.7) | |
| Pre-gestational diabetes | <0.001 | ||
| No | 11,089 (96.9) | 11,374 (99.4) | |
| Yes | 359 (3.1) | 64 (0.6) | |
| Periconceptional maternal smokinga | 0.001 | ||
| No | 9223 (78.8) | 9370 (80.5) | |
| Yes | 2481 (21.2) | 2266 (19.5) | |
| Periconceptional maternal alcohol use | 0.002 | ||
| No | 7414 (64.7) | 7138 (62.7) | |
| Yes | 4047 (35.3) | 4239 (37.3) | |
| Periconceptional maternal folic acid supplement use | 0.09 | ||
| No | 1712 (14.7) | 1611 (14.0) | |
| Yes | 9911 (85.3) | 9934 (86.0) | |
| Family history of CHD | <0.001 | ||
| No | 11,255 (96.2) | 11,497 (98.8) | |
| Yes | 449 (3.8) | 139 (1.2) | |
| Periconceptional UTI | 0.001 | ||
| No | 10,682 (91.3) | 10,758 (92.4) | |
| Yes | 1022 (8.7) | 878 (7.6) | |
| Periconceptional fever associated with UTI | 0.04 | ||
| No | 11,383 (97.3) | 11,367 (97.7) | |
| Yes | 321 (2.7) | 269 (2.3) | |
| Periconceptional antibiotic useb at the time of the UTI | 0.04 | ||
| No | 10,898 (93.4) | 10,926 (94.0) | |
| Yes | 772 (6.6) | 695 (6.0) |
Abbreviation: UTI, urinary tract infection.
a
Mother reported any smoking between 1 month prior to conception to end of first trimester.
b
Sulfonamides, nitrofurantoin, cephalosporins, penicillin, macrolides, and quinolones.