Skip to main content
. 2004 Aug;94(8):1358–1365. doi: 10.2105/ajph.94.8.1358

TABLE 1—

Characteristics of African American and White Women and Risk Ratios (RRs) for Preterm Birth: Women With Pregnancies Initiated April 1996–August 2000

African American Women (n = 724) White Women (n = 1174)
No. % Preterm RR (95% CI) No. % Preterm RR (95% CI)
Mother’s education, y
    < 12 176 8.0 0.6 (0.3, 1.1) 166 14.5 1.0 (0.6, 1.6)
    12a 277 13.4 1.0 276 14.9 1.0
    > 12 271 13.3 1.0 (0.6, 1.5) 732 9.6 0.6 (0.4, 0.9)
Mother’s age at 24 weeks’ gestation, y
    16–19 149 8.1 0.7 (0.4, 1.3) 112 11.6 1.0 (0.5, 1.7)
    20–29a 434 11.1 1.0 568 12.5 1.0
    ≥ 30 141 19.2 1.7 (1.1, 2.7) 494 10.7 0.9 (0.6, 1.2)
Parity
    0a 328 10.1 1.0 562 9.1 1.0
    1 213 13.2 1.3 (0.8, 2.1) 359 14.8 1.6 (1.1, 2.3)
    ≥ 2 178 14.0 1.4 (0.9, 2.3) 248 12.5 1.4 (0.9, 2.1)
    Missing information 5 5
Marital status
    Not marrieda 535 11.0 1.0 314 12.4 1.0
    Married 186 14.5 1.3 (0.9, 2.0) 860 11.2 0.9 (0.6, 1.3)
    Missing information 3 0
Height, inches
    < 62 71 14.1 1.2 (0.7, 2.3) 107 15.0 1.2 (0.8, 2.0)
    62 to < 68a 512 11.5 1.0 872 12.0 1.0
    ≥ 68 113 13.3 1.2 (0.7, 2.0) 172 7.6 0.6 (0.4, 1.1)
    Missing information 28 23
Prepregnancy BMI
    Underweight (< 19.8) 90 8.9 0.8 (0.4, 1.7) 190 11.1 1.0 (0.6, 1.5)
    Normal weight (19.8–26.0)a 280 11.1 1.0 622 11.4 1.0
    Overweight (> 26.0–29.0) 80 8.8 0.8 (0.4, 1.7) 115 11.3 1.0 (0.6, 1.7)
    Obese (> 29.0) 229 14.9 1.3 (0.9, 2.1) 205 12.7 1.1 (0.7, 1.7)
    Missing information 45 42
Poverty index, % of federal poverty threshold
    < 50 93 11.8 1.0 (0.5, 2.0) 33 12.1 1.1 (0.4, 2.8)
    50 to < 100 170 15.9 1.3 (0.7, 2.3) 137 13.9 1.2 (0.8, 2.0)
    100 to < 200 202 10.4 0.9 (0.5, 1.6) 235 11.5 1.0 (0.7, 1.5)
    ≥ 200a 141 12.1 1.0 678 11.2 1.0
    Missing information 118 91
BV
    No BVa 554 12.3 1.0 1026 11.3 1.0
    BV detected 141 11.4 0.9 (0.6, 1.5) 87 11.5 1.0 (0.6, 1.9)
    Missing information 29 61
Clinic site
    University care site 335 16.4 2.0 (1.3, 3.0) 900 12.6 1.6 (1.0, 2.4)
    Public health departmenta 389 8.2 1.0 274 8.0 1.0
Alcohol use during pregnancy, drinks/week
    < 5 drinks/weeka 660 11.7 1.0 1111 11.5 1.0
    ≥ 5 drinks/week 5 40.0 3.4 (1.1, 10.2) 11 0 . . .b
    Missing information 59 52
Smoked during months 1–6 of pregnancy, cigarettes/day
    Nonea 541 11.5 1.0 807 10.8 1.0
    1–9 cigarettes/day 86 14.0 1.2 (0.7, 2.2) 147 13.6 1.3 (0.8, 2.0)
    10–19 cigarettes/day 19 15.8 1.4 (0.5, 4.0) 99 16.2 1.5 (0.9, 2.4)
    ≥ 20 cigarettes/day 7 14.3 1.2 (0.2, 7.8) 43 11.6 1.1 (0.5, 2.5)
    Missing information 71 78

Notes. CI = confidence interval; BMI = body mass index; BV = bacterial vaginosis.

aReference category.

bToo few cases to calculate risk ratio.