Risk Factors for Preterm Birth among HIV-Infected Tanzanian Women: A Prospective Study
Table 3
Risk factors for very preterm birth (<34 weeks versus ≥37 weeks), .
Characteristic
Unadjusted
Adjusteda
RR [95% CI]
value
RR [95% CI]
value
Sociodemographic
Age < 20 at conception
2.21 [1.37, 3.55]
0.001
1.94 [1.22, 3.06]
0.005
No partner
1.20 [0.66, 2.16]
0.55
Illiterate
1.93 [1.09, 3.41]
0.02
1.66 [0.91, 3.02]
0.10
Nutrition
Plasma vitamin A < 20 (µg/dL)
1.89 [1.24, 2.87]
0.003
1.38 [0.89, 2.13]
0.15
Plasma vitamin E < 9.7 (µmol/L)
0.86 [0.57, 1.32]
0.50
Selenium (mg/mL)
0.003 [<0.01, 58]
0.24
<0.11
1.64 [0.87, 3.09]
0.11-0.12
1.13 [0.53, 2.40]
0.12–0.14
1.82 [1.00, 3.32]
≥0.14
Reference
Hemoglobin (g/dL)
0.45
<7.0
0.72 [0.43, 1.23]
7.0–8.4
0.72 [0.43, 1.23]
8.5–10.9
1.12 [0.63, 2.01]
≥11.0
Reference
Mid-upper arm circumference (cm)
0.03
0.03
≤23.5
1.90 [0.99, 3.67]
2.07 [1.03, 4.16]
23.6–25.0
1.50 [0.75, 3.00]
1.50 [0.74, 3.06]
25.1–27.5
1.10 [0.52, 2.32]
1.03 [0.49, 2.20]
>27.5
Reference
Reference
Weight gain (g per week)
<0.0001
0.0005
≤0
3.21 [2.06, 5.00]
2.32 [1.36, 3.96]
1–120
1.78 [1.05, 3.03]
1.85 [1.05, 3.25]
≥120
Reference
Reference
Height < 150 cm
0.93 [0.47, 1.86]
0.84
Infections
Malaria
2.03 [1.34, 3.07]
0.0009
1.87 [1.20, 2.89]
0.005
Hookworm
1.18 [0.61, 2.27]
0.63
Entamoeba coli
2.34 [1.36, 4.02]
0.002
2.38 [1.38, 4.09]
0.002
Ascaris lumbricoides
1.34 [0.58, 3.13]
0.49
Cryptosporidium parvum
0.64 [0.17, 2.50]
0.53
Entamoeba histolytica
2.44 [0.89, 6.66]
0.08
2.62 [1.09, 6.28]
0.03
Strongyloides stercoralis
0.86 [0.13, 5.65]
0.88
Trichuris trichiura
No data
Trichomoniasis
1.30 [0.84, 1.99]
0.24
Syphilis
1.34 [0.58, 3.13]
0.49
Vaginal candidiasis
0.82 [0.27, 2.45]
0.72
Gonorrhea
2.61 [0.80, 8.57]
0.11
2.72 [0.86, 8.58]
0.09
HIV/AIDS
WHO HIV disease stage ≥ 2
2.09 [1.39, 3.14]
0.0004
1.67 [1.11, 2.51]
0.01
CD4 count < 200 cells/mm3
0.72 [0.36, 1.45]
0.36
Viral load ≥ 50,000 copies/mL
0.79 [0.46, 1.36]
0.40
Other clinical variables
Twins
2.06 [0.85, 5.00]
0.11
1.86 [0.68, 5.07]
0.22
Prehypertension or hypertensionb
1.16 [0.76, 1.79]
0.49
1.22 [0.81, 1.85]
0.33
ARR: risk ratio; CI: confidence interval.
aAdjusted for age < 20 years, literacy, plasma vitamin A < 20 µg/dL, mid-upper arm circumference, weight gain, malaria, Entamoeba coli, Entamoeba histolytica, gonorrhea, WHO HIV disease stage ≥ 2, twins, and prehypertension or hypertension.
bSystolic blood pressure > 120 mmHg or diastolic blood pressure > 80 mmHg.
