Reply to NW Solomons

¹ Department of Population and Family Health Sciences, Bloomberg School of Public Health, The Johns Hopkins University, 615 North Wolfe Street, Room W4033, Baltimore, MD 21205, E-mail: mdreyfus{at}jhsph.edu
² Departments of Community Health and Obstetrics and Gynecology, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania
³ Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA 02115

Dear Sir:

In our recent publication on the determinants of low birth weight (LBW) among HIV-infected pregnant women in Dar es Salaam, Tanzania, we reported incidence rates of LBW (11.1%), preterm delivery (23.5%), and small-for-gestational-age (SGA) birth (11.5%) among a cohort of women who participated in a randomized, double-blind, placebo-controlled trial of antenatal multivitamin and vitamin A supplementation (1). Multivitamin supplementation significantly decreased the risk of fetal loss, LBW, severely preterm delivery, and SGA birth in this cohort, but vitamin A supplementation had no significant effect (2). Among women who were randomly assigned to receive no multivitamins (placebo or vitamin A only), the rates of LBW, preterm delivery, and SGA birth were 15.8%, 24.5%, and 17.6%, respectively (2). This LBW rate falls within the range reported from numerous studies of HIV-infected pregnant women in sub-Saharan Africa: from 9% in Nairobi, Kenya (3), to 26% in Kigali, Rwanda (4). Most of these studies were conducted in urban settings similar to that of our study, but the prevalence of symptomatic HIV infection or AIDS in these cohorts varied greatly.

We recently published findings from our study cohort examining the association of HIV infection and adverse pregnancy outcomes (5). This analysis was limited to women who were randomly assigned to receive no multivitamins because of the significant effect of multivitamin supplements on the risk of adverse pregnancy outcomes previously reported in this cohort (2). We concurrently enrolled and followed 502 HIV-uninfected pregnant women in addition to our trial cohort of 1078 HIV-infected women, and we found no significant differences between these 2 groups in poor pregnancy outcomes, including the risk of fetal loss, LBW, and preterm delivery (5). However, we found significantly higher relative risks (RRs) of LBW (RR: 2.29; 95% CI: 1.34, 3.92) and preterm delivery (RR: 1.93; 95% CI: 1.35, 2.77) among symptomatic HIV-infected women than among HIV-uninfected women (5). The rates of LBW were 14.7%, 13.0%, and 26.4% in HIV-uninfected, asymptomatic HIV-infected, and symptomatic HIV-infected women, respectively. Symptomatic HIV-infected women (World Health Organization stage II or higher) made up 16.6% of this cohort. Braddick et al (3) reported a 17% LBW rate among women in Kenya with HIV-related diseases compared with a 6% LBW rate among women who were asymptomatic or had generalized lymphadenopathy alone (odds ratio: 3.4; P = 0.08). LBW was rare (3%) among uninfected women in the study. Ryder et al (6) reported LBW rates of 9.8%, 16.9%, and 32.9% among Rwandan women who were HIV uninfected, HIV infected without AIDS, and HIV infected with AIDS, respectively.

In the Brocklehurst and French (7) meta-analysis of HIV infection and perinatal outcomes, a modest relation was observed between HIV infection and LBW, but there was considerable heterogeneity among study results. The reported association was stronger in studies from developing countries than in those from developed countries. Compared with HIV-infected women in developed countries, infected women in developing countries are more likely to be at advanced clinical and immunologic stages of HIV-related disease, possibly because of the high prevalence of undernutrition, opportunistic infections, and poor access to treatment. These conditions increase the risk of poor pregnancy outcomes regardless of HIV status, and they may be important contributors to the high rates observed among HIV-infected women, particularly those with symptoms of HIV-related disease. Our findings support those of the metaanalysis and suggest that the increased risk of LBW and preterm delivery associated with HIV infection may be due in large part to the more advanced disease in some HIV-infected women.

REFERENCES

1. Dreyfuss ML, Msamanga GI, Spiegelman D, et al. Determinants of low birth weight among HIV-infected pregnant women in Tanzania. Am J Clin Nutr 2001;74:814–26.
2. Fawzi WW, Msamanga GI, Spiegelman D, et al. Randomised trial of effects of vitamin supplements on pregnancy outcomes and T cell counts in HIV-1-infected women in Tanzania. Lancet 1998;351:1477–82.
3. Braddick MR, Kreiss JK, Embree JE, et al. Impact of maternal HIV infection on obstetrical and early neonatal outcome. AIDS 1990;4:1001–5.
4. Leroy V, Ladner J, Nyiraziraje M, et al. Effect of HIV-1 infection on pregnancy outcome in women in Kigali, Rwanda, 1992–1994. Pregnancy and HIV Study Group. AIDS 1998;12:643–50.
5. Coley JL, Msamanga GI, Fawzi MC, et al. The association between maternal HIV-1 infection and pregnancy outcomes in Dar es Salaam, Tanzania. Br J Obstet Gynaecol 2001;108:1125–33.
6. Ryder RW, Nsa W, Hassig SE, et al. Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire. N Engl J Med 1989;320:1637–42.
7. Brocklehurst P, French R. The association between maternal HIV infection and perinatal outcome: a systemic review of the literature and meta-analysis. Br J Obstet Gynaecol 1998;105:836–48.