Characteristic | Case infants (n = 20,151) Mean ± SD |  | Control infants (n = 668,381) Mean ± SD |  |
---|---|---|---|---|
Maternal age at delivery | 26.8 ± 6.2 |  | 26.9 ± 6.1 |  |
 Missing | 0 |  | 3 |  |
 | n | (%) | n | (%) |
Maternal race/ethnicity | Â | Â | Â | Â |
 Non-Hispanic White | 11,658 | (57.9) | 381,262 | (57.0) |
 Non-Hispanic Black | 4,751 | (23.6) | 152,370 | (22.8) |
 Hispanic | 2,976 | (14.8) | 106,003 | (15.9) |
 Othera | 745 | (3.7) | 28,009 | (4.2) |
 Missing | 21 | (<0.1) | 737 | (<0.1) |
Maternal educationb | Â | Â | Â | Â |
 < High school | 5,035 | (25.0) | 151,732 | (22.7) |
 High school | 5,934 | (29.4) | 190,393 | (28.5) |
 > High school | 9,125 | (45.3) | 324,228 | (48.5) |
 Missing | 57 | (0.3) | 2,028 | (0.3) |
Infant sex | Â | Â | Â | Â |
 Female | 7,684 | (38.1) | 327,520 | (49.0) |
 Male | 12,463 | (61.8) | 340,858 | (51.0) |
 Missing | 4 | (0.2) | 3 | (<0.1) |