Table 2.
Major risk factors of preterm birth (PTB), very PTB and late PTB* in Black mothers** at the Boston Medical Center.
| PTB | Very PTB | Late PTB | |||||||
|---|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | p | OR | 95% CI | p | OR | 95% CI | p | |
| Epidemiologic Factors | |||||||||
| Smoking | 1.3 3 | 1.08–1.64 | 0.007 | 1.2 8 | 0.98–1.66 | 0.07 | 1.3 8 | 1.09–1.75 | 0.007 |
| Illicit drug use | 1.4 8 | 0.97–2.25 | 0.07 | 1.6 0 | 0.95–2.68 | 0.08 | 1.4 1 | 0.88–2.27 | 0.15 |
| Overall Stress | 1.3 0 | 1.06–1.60 | 0.01 | 1.1 3 | 1.00–1.28 | 0.05 | 1.2 4 | 0.98–1.58 | 0.07 |
| Genetic Ancestry | |||||||||
| Ancestry a | 1.1 1 | 1.02–1.20 | 0.01 | 1.1 7 | 1.03–1.33 | 0.01 | 1.0 6 | 0.97–1.16 | 0.22 |
| Gene-Environment Interactions | |||||||||
| CYP1A1 b | 1.0 1 | 0.70–1.45 | 0.96 | 0.9 2 | 0.58–1.46 | 0.74 | 1.0 7 | 0.71–1.61 | 0.76 |
| CYP1A1 x smoking | 1.8 3 | 1.20–2.81 | 0.005 | 1.5 2 | 0.91–2.55 | 0.11 | 2.0 3 | 1.30–3.19 | 0.002 |
| GSTT1 c | 0.7 8 | 0.53–1.16 | 0.23 | 0.7 5 | 0.45–1.25 | 0.28 | 0.8 1 | 0.51–1.27 | 0.35 |
| GSTT1 x smoking | 1.2 8 | 0.81–2.03 | 0.28 | 1.5 6 | 0.93–2.61 | 0.09 | 1.0 6 | 0.61–1.86 | 0.83 |
Note:
*
PTB: preterm birth with gestational age <37 weeks; very PTB: preterm birth with gestational age <34 weeks; late PTB: preterm birth with gestational age 34.0–36.86 weeks.
**
Based on self-reported Black race.
a
Ancestry is defined as African ancestry proportion and OR is expressed for each 10% increment of African ancestry.
b
CYP1A1 (AA) as the reference group.
c
GSTT1 (present) as the reference group.