Table 1.
Selected characteristics of the participants
| Characteristic | No. | Percent |
|---|---|---|
| For mothers | ||
| Age at child’s birth, years, mean ± s.d. | 25.5 ± 5.6 | |
| Race | ||
| White | 197 | 89.1% |
| African-American | 19 | 8.6% |
| Asian/Pacific Islander/Other | 5 | 2.3% |
| ABO blood type | ||
| A | 78 | 35.3% |
| B | 29 | 13.1% |
| AB | 18 | 8.2% |
| O | 96 | 43.4% |
| Rh blood type | ||
| Positive | 192 | 86.9% |
| Negative | 29 | 13.1% |
| For children | ||
| Weight at birth, g, mean ± s.d. | 3,149 ± 570.7 | |
| Sex | ||
| Male | 93 | 42.1% |
| Female | 128 | 57.9% |
| Lesion level | ||
| Thoracic | 91 | 41.2% |
| Lumbar | 115 | 52.0% |
| Sacral | 15 | 6.8% |
| Shunted hydrocephalus | ||
| Yes | 176 | 79.6% |
| No | 45 | 20.4% |
| Year of birth, mean ± s.d. | 1981.6 ± 10.5 | |
| Birth before/after 1 January 1998† | ||
| Before | 202 | 91.4% |
| After | 19 | 8.6% |
†
Date of mandatory folic acid grain fortification in the United States