Determinants of low birth weight among HIV-infected pregnant women in Tanzania.
BACKGROUND
Low birth weight (LBW) increases the risk of infant death, but little is known about its causes among HIV-infected populations in sub-Saharan Africa.


OBJECTIVE
We assessed sociodemographic, nutritional, immunologic, parasitic, and infant risk factors for birth weight, LBW, and small-for-gestational-age (SGA) status in a cohort of 822 HIV-positive women enrolled in a clinical trial of vitamin supplementation and pregnancy outcomes in Dar es Salaam, Tanzania.


METHODS
Women were enrolled at prenatal care clinics during their second trimester, at which time blood, stool, urine, and genital specimens were collected, and anthropometric measurements and sociodemographic data were recorded. Birth weight was measured at hospital delivery.


RESULTS
The mean (+/-SD) birth weight was 3015 +/- 508 g, 11.1% of newborns weighed <2500 g (LBW), and 11.5% were SGA. In multivariate analyses, maternal weight at enrollment and a low CD8 cell count were inversely associated with LBW. Advanced-stage HIV disease, previous history of preterm birth, Plasmodium falciparum malaria, and any helmintic infection were associated with higher risk of LBW. The intestinal parasites Entamoeba histolytica and Strongyloides stercoralis were predictors of LBW despite their low prevalence in the cohort. In a multivariate-adjusted linear regression model, BMI, midupper arm circumference, a CD4 cell count <200 x 10(6) cells/L (200 cells/mm(3)), primiparity, maternal literacy, and infant HIV infection at birth were significantly associated with birth weight in addition to risk factors included in the LBW model. Determinants of SGA included maternal weight, low serum vitamin E concentration, candidiasis, malaria, and infant HIV infection at birth.


CONCLUSIONS
Prevention of HIV disease progression and vertical transmission, improved nutritional status, and better management of malaria and intestinal parasitic infections are likely to reduce the incidence of LBW in Tanzania.
Dreyfuss
M L
ML
Departments of Nutrition, Biostatistics, and Epidemiology, Harvard School of Public Health, Boston, MA, USA. mdreyfus@jhsph.edu
Msamanga
G I
GI
Spiegelman
D
D
Hunter
D J
DJ
Urassa
E J
EJ
Hertzmark
E
E
Fawzi
W W
WW
D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000150:complications*; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight / Q000097:blood* / Q000276:immunology; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D018655:Lymphocyte Count; D008288:Malaria / Q000150:complications; D008429:Maternal Welfare; D008875:Middle Aged; D016017:Odds Ratio; D010272:Parasitic Diseases / Q000150:complications; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood / Q000469:parasitology / Q000821:virology*; D011256:Pregnancy Outcome; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013636:Tanzania