Table 1.
Demographic, clinical and genetic characteristics of BMC cohort, by preterm status
| Preterm delivery (N = 571) | Term delivery (N = 1,178) | P | |
|---|---|---|---|
| Demographic characteristics | |||
| Age (%) | |||
| <20 | 11.2 | 11.2 | 0.15 |
| 20–24 | 24.3 | 27.3 | |
| 25–29 | 24.5 | 25.2 | |
| 30–34 | 21.4 | 22.2 | |
| ≥35 | 18.6 | 14.0 | |
| Ethnicity (%) | |||
| African Americans | 57.4 | 52.6 | 0.17 |
| Caucasians | 13.8 | 13.1 | |
| Hispanic Americans | 23.6 | 25.8 | |
| Education (%) | |||
| ≤Middle school | 29.6 | 34.5 | 0.38 |
| =High school | 38.0 | 31.9 | |
| >High school | 32.4 | 33.6 | |
| Parity (%) | |||
| 0 | 40.5 | 37.0 | 0.54 |
| 1 | 26.6 | 30.9 | |
| ≥2 | 32.9 | 32.1 | |
| Marital status (%) | |||
| Married | 32.1 | 37.0 | 0.04 |
| Others | 67.9 | 63.0 | |
| Smoking during pregnancy (%) | |||
| Never | 75.3 | 84.7 | <0.01 |
| Quitter | 4.8 | 3.4 | |
| Persistent | 19.9 | 11.9 | |
| Passive smoking during pregnancy (%) | |||
| No | 77.5 | 70.6 | <0.01 |
| Yes | 22.5 | 29.4 | |
| Illicit drug use (%) | |||
| No | 82.8 | 91.0 | <0.01 |
| Yes | 17.2 | 9.0 | |
| Alcohol use (%) | |||
| No | 95.3 | 94.2 | 0.37 |
| Yes | 4.7 | 5.8 | |
| Maternal pre-pregnant BMI (%) | |||
| <20 | 15.2 | 12.1 | 0.03 |
| 20–24 | 35.6 | 40.7 | |
| 25–29 | 28.9 | 30.7 | |
| 30+ | 20.3 | 16.6 | |
| Infant sex (%) | |||
| Male | 48.7 | 50.3 | 0.52 |
| Female | 51.3 | 49.7 | |
| Clinical characteristics | |||
| Gestational age (week) | 33.6 (3.4) | 39.7 (1.1) | <0.01 |
| Birth weight (g) | 2,144.1 (748.3) | 3,375.1 (460.2) | <0.01 |
| Genotype counts and frequency [n (%)] | |||
| CYP1A1 | |||
| AA | 323 (56.6) | 674 (57.2) | 0.70 |
| Aa | 206 (36.1) | 395 (33.5) | |
| Aa | 42 (7.3) | 109 (9.3) | |
| GSTT1 | |||
| Present | 440 (77.1) | 895 (76.0) | 0.60 |
| Absent | 131 (22.9) | 283 (24.0) | |