Table 1. Characteristics of the preterm pregnancies resulted in live births and NEC-related infant mortality, Birth and Infant Death Cohort, 2000–2004.
| Characteristic | Live birth (n = 1,315,493) | NEC infant death (n = 1,122) | Early neonatal death 0–6 days (n = 83) | Late neonatal death 7–27 days (n = 928) | Postneonatal death 28–364 days (n = 111) |
|---|---|---|---|---|---|
| Maternal smoking | |||||
| Non-smokers | 86.9% | 83.5% | 84.3% | 83.4% | 83.8% |
| Light smokers | 5.3% | 7.3% | 7.2% | 7.4% | 6.3% |
| Heavy smokers | 7.8% | 9.2% | 8.4% | 9.2% | 9.9% |
| Maternal age, years | |||||
| ≤ 19 | 13.3% | 19.4% | 16.9% | 19.2% | 23.4% |
| 20–34 | 72.3% | 68.8% | 67.5% | 68.9% | 69.4% |
| ≥35 | 14.4% | 11.8% | 15.7% | 12.0% | 7.2% |
| Maternal race/ethnicity | |||||
| Non-Hispanic White | 55.9% | 34.7% | 31.3% | 34.4% | 39.6% |
| Hispanic | 17.1% | 15.9% | 20.5% | 15.5% | 15.3% |
| Non-Hispanic Black | 23.4% | 46.0% | 43.4% | 46.4% | 44.1% |
| Asian | 3.7% | 3.5% | 4.8% | 3.7% | 0.9% |
| Maternal education, years | |||||
| <12 | 23.5% | 32.5% | 33.7% | 32.7% | 30.6% |
| =12 | 33.3% | 37.0% | 44.6% | 35.7% | 42.3% |
| 13–16 | 34.9% | 26.3% | 19.3% | 27.3% | 23.4% |
| ≥17 | 8.2% | 4.2% | 2.4% | 4.4% | 3.6% |
| Maternal marital status | |||||
| Married | 59.2% | 40.8% | 42.2% | 41.4% | 35.1% |
| Unmarried | 40.8% | 59.2% | 57.8% | 58.6% | 64.9% |
| Month that prenatal care started | |||||
| 1st Trimester | 80.8% | 77.8% | 73.5% | 78.8% | 73.0% |
| 2nd Trimester | 13.6% | 15.2% | 21.7% | 14.4% | 17.1% |
| 3rd Trimester | 2.8% | 1.4% | 2.4% | 1.4% | 0.9% |
| No prenatal care | 2.9% | 5.5% | 2.4% | 5.4% | 9.0% |
| Gestational age at delivery, weeks | |||||
| 24–26 | 3.0% | 41.3% | 14.5% | 42.1% | 54.1% |
| 27–29 | 4.4% | 32.9% | 15.7% | 33.9% | 36.9% |
| 30–32 | 9.4% | 16.4% | 27.7% | 16.4% | 8.1% |
| 33–36 | 83.1% | 9.4% | 42.2% | 7.5% | 0.9% |
| Infant sex | |||||
| Male | 53.9% | 58.1% | 61.4% | 58.3% | 54.1% |
| Female | 46.1% | 41.9% | 38.6% | 41.7% | 45.9% |