Table 2. Association of maternal light and heavy smoking and NEC infant mortality in preterm babies, Birth and Infant Death Cohort, 2000–2004.
| Smoking | Non-smoking | Adjusted OR | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Light smoking (<10 cigs/day) | Heavy smoking (≥10 cigs/day) | <10 cigs/day | ≥10 cigs/day | ||||||||
| Death case | Live birth | Mortality rate (per 10,000) | Death case | Live birth | Mortality (per 10,000) | Death case | Live birth | Mortality (per 10,000) | OR (95% Cl) | OR (95% Cl) | |
| Totala | 82 | 69,589 | 11.8 | 103 | 102,507 | 10.0 | 937 | 1,143,397 | 8.2 | 1.21 (1.03, 1.43) | 1.31 (1.12, 1.52) |
| Birthweight (g)b | |||||||||||
| <750 | 16 | 1,404 | 114.0 | 20 | 1,697 | 117.9 | 263 | 20,858 | 126.1 | 0.83 (0.58, 1.20) | 0.92 (0.66, 1.30) |
| 750–999 | 24 | 2,028 | 118.3 | 34 | 2,728 | 124.6 | 263 | 29,002 | 90.7 | 1.29 (0.95, 1.76) | 1.58 (1.20, 2.09) |
| 1000–1499 | 34 | 4,889 | 69.5 | 33 | 6,977 | 47.3 | 265 | 66,825 | 39.7 | 1.64 (1.26, 2.13) | 1.37 (1.04, 1.81) |
| 1500–1999 | 5 | 9,178 | 5.4 | 11 | 13,827 | 8.0 | 95 | 120,185 | 7.9 | 0.64 (0.33, 1.22) | 1.11 (0.69, 1.78) |
| 2000–2499 | 3 | 19,562 | 1.5 | 3 | 30,331 | 1.0 | 36 | 257,715 | 1.4 | 1.27 (0.54, 2.98) | 1.09 (0.45, 2.64) |
| ≥2500 | 0 | 32,528 | — | 2 | 46,947 | 0.4 | 15 | 648,812 | 0.2 | — | 1.66 (0.54, 5.09) |
| Gestational age, wkc | |||||||||||
| 24—26 | 26 | 2,329 | 111.6 | 36 | 3,005 | 119.8 | 401 | 34,248 | 117.1 | 0.92 (0.69, 1.22) | 1.12 (0.86, 1.45) |
| 27—29 | 39 | 3,479 | 112.1 | 32 | 4,752 | 67.3 | 298 | 50,134 | 59.4 | 1.75 (1.37, 2.24) | 1.19 (0.90, 1.56) |
| 30—32 | 13 | 7,366 | 17.6 | 29 | 10,480 | 27.7 | 142 | 106,208 | 13.4 | 1.23 (0.82, 1.86) | 2.39 (1.75, 3.26) |
| 33—36 | 4 | 56,415 | 0.7 | 6 | 84,270 | 0.7 | 96 | 952,807 | 1.0 | 0.60 (0.29, 1.23) | 0.80 (0.43, 1.47) |
| Infant sexd | |||||||||||
| Male | 46 | 37,151 | 12.4 | 52 | 54,834 | 9.5 | 554 | 616,626 | 9.0 | 1.15 (0.92, 1.43) | 1.10 (0.88, 1.36) |
| Female | 36 | 32,438 | 11.1 | 51 | 47,673 | 10.7 | 383 | 526,771 | 7.3 | 1.31 (1.02, 1.69) | 1.62 (1.29, 2.02) |
| Maternal race/ethnicitye | |||||||||||
| White | 45 | 43,732 | 10.3 | 73 | 85,745 | 8.5 | 271 | 605,295 | 4.5 | 1.69 (1.34, 2.13) | 1.44 (1.18, 1.75) |
| Hispanic | 2 | 5,306 | 3.8 | 7 | 3,227 | 21.7 | 169 | 216,019 | 7.8 | 0.41 (0.15, 1.12) | 2.42 (1.40, 4.20) |
| Black | 34 | 19,496 | 17.4 | 22 | 12,777 | 17.2 | 460 | 275,061 | 16.7 | 1.02 (0.79, 1.31) | 1.02 (0.75, 1.40) |
| Asian | 1 | 1,055 | 9.5 | 1 | 758 | 13.2 | 37 | 47,022 | 7.9 | 0.97 (0.23, 4.17) | 1.15 (0.25, 5.33) |
aOR adjusted for maternal race/ethnicity, age, education, marital status; prenatal care began, gestational age, infant sex, and birth year.
bOR adjusted for maternal race/ethnicity, age, education, marital status; prenatal care began, gestational age, infant sex, and birth year.
cOR adjusted for maternal race/ethnicity, age, education, marital status; prenatal care began, infant sex, and birth year.
dOR adjusted for maternal race/ethnicity, age, education, marital status; prenatal care began, gestational age, and birth year.
eOR adjusted for maternal age, education, marital status; prenatal care began, gestational age, infant sex, and birth year.