Risk Factors for Preterm Birth among HIV-Infected Tanzanian Women: A Prospective Study
Table 2
Risk factors for preterm birth (<37 weeks versus ≥37 weeks), .
Characteristic
Unadjusted
Adjusteda
RR [95% CI]
value
RR [95% CI]
value
Sociodemographic
Age < 20 at conception
1.58 [1.18, 2.11]
0.002
1.47 [1.10, 1.97]
0.01
No partner
1.17 [0.84, 1.63]
0.35
Illiterate
1.58 [1.14, 2.20]
0.006
1.53 [1.09, 2.15]
0.01
Nutrition
Plasma vitamin A < 20 (µg/dL)
1.24 [1.19, 1.96]
0.0008
1.25 [0.97, 1.62]
0.08
Plasma vitamin E < 9.7 (µmol/L)
0.88 [0.69, 1.13]
0.31
Selenium (mg/mL)
0.12
0.16
<0.11
1.37 [0.97, 1.96]
1.40 [0.98, 2.00]
0.11-0.12
1.15 [0.77, 1.73]
1.11 [0.74, 1.65]
0.12–0.14
1.39 [0.98, 1.95]
1.48 [1.05, 2.08]
≥0.14
Reference
Reference
Hemoglobin (g/dL)
0.11
0.90
<7.0
1.29 [0.83, 2.01]
0.98 [0.64, 1.52]
7.0–8.4
1.05 [0.74, 1.49]
0.90 [0.63, 1.28]
8.5–10.9
0.82 [0.60, 1.11]
0.78 [0.58, 1.07]
≥11.0
Reference
Reference
Mid-upper arm circumference (cm)
0.19
0.23
≤23.5
1.29 [0.92, 1.81]
1.32 [0.93, 1.87]
23.6–25.0
0.95 [0.66, 1.39]
0.91 [0.63, 1.33]
25.1–27.5
1.11 [0.78, 1.58]
1.07 [0.75, 1.53]
>27.5
Reference
Reference
Weight gain (g per week)
<0.0001
0.006
≤0
1.95 [1.51, 2.53]
1.60 [1.20, 2.14]
1–120
1.18 [0.85, 1.65]
1.12 [0.81, 1.57]
≥120
Reference
Reference
Height < 150 cm
0.95 [0.64, 1.40]
0.79
Infections
Malaria
1.53 [1.20, 1.96]
0.0006
1.41 [1.10, 1.81]
0.006
Hookworm
1.30 [0.92, 1.84]
0.13
1.19 [0.83, 1.70]
0.34
Entamoeba coli
1.49 [1.04, 2.14]
0.03
1.49 [1.04, 2.15]
0.03
Ascaris lumbricoides
1.21 [0.73, 1.99]
0.46
Cryptosporidium parvum
0.88 [0.45, 1.72]
0.70
Entamoeba histolytica
1.73 [0.92, 3.27]
0.09
1.79 [0.99, 3.26]
0.06
Strongyloides stercoralis
1.23 [0.53, 2.84]
0.63
Trichuris trichiura
1.44 [0.56, 3.65]
0.45
Trichomoniasis
1.18 [0.92, 1.52]
0.19
1.13 [0.88, 1.45]
0.35
Syphilis
1.28 [0.80, 2.05]
0.31
Vaginal candidiasis
1.10 [0.66, 1.85]
0.72
Gonorrhea
1.83 [0.88, 3.85]
0.11
1.68 [0.84, 3.35]
0.14
HIV/AIDS
WHO HIV disease stage ≥ 2
1.60 [1.26, 2.03]
0.0001
1.40 [1.11, 1.78]
0.005
CD4 count < 200 cells/mm3
0.92 [0.64, 1.32]
0.65
Viral load ≥ 50,000 copies/mL
1.02 [0.74, 1.42]
0.89
Other clinical variables
Twins
1.50 [0.85, 2.64]
0.16
1.85 [0.94, 3.66]
0.07
Prehypertension or hypertensionb
1.25 [0.98, 1.58]
0.07
1.27 [1.01, 1.60]
0.04
ARR: risk ratio; CI: confidence interval.
aAdjusted for age < 20 years, literacy, plasma vitamin A < 20 g/dL, selenium, mid-upper arm circumference, weight gain, malaria, hookworm, Entamoeba coli, Entamoeba histolytica, trichomoniasis, gonorrhea, WHO HIV disease stage ≥ 2, twins, and prehypertension or hypertension.
bSystolic blood pressure >120 mmHg or diastolic blood pressure >80 mmHg.
