HIV-1 disease progression in breast-feeding and formula-feeding mothers: a prospective 2-year comparison of T cell subsets, HIV-1 RNA levels, and mortality

Abstract

Background: There is conflicting evidence regarding the effects of breast-feeding on maternal mortality from human immunodeficiency virus type 1 (HIV-1) infection, and little is known about the effects of breast-feeding on markers of HIV-1 disease progression.

Methods: HIV-1-seropositive women were enrolled during pregnancy and received short-course zidovudine. HIV-1 RNA levels and CD4 cell counts were determined at baseline and at months 1, 3, 6, 12, 18, and 24 postpartum and were compared between breast-feeding and formula-feeding mothers.

Results: Of 296 women, 98 formula fed and 198 breast-fed. At baseline, formula-feeding women had a higher education level and prevalence of HIV-1-related illness than did breast-feeding women; however, the groups did not differ with respect to CD4 cell counts and HIV-1 RNA levels. Between months 1 and 24 postpartum, CD4 cell counts decreased 3.9 cells/ microL/month (P<.001), HIV-1 RNA levels increased 0.005 log(10) copies/mL/month (P=.03), and body mass index (BMI) decreased 0.03 kg/m(2)/month (P<.001). The rate of CD4 cell count decline was higher in breast-feeding mothers (7.2 cells/ microL/month) than in mothers who never breast-fed (4.0 cells/ microL/month) (P=.01). BMI decreased more rapidly in breast-feeding women (P=.04), whereas HIV-1 RNA levels and mortality did not differ significantly between breast-feeding and formula-feeding women.

Conclusions: Breast-feeding was associated with significant decreases in CD4 cell counts and BMI. HIV-1 RNA levels and mortality were not increased, suggesting a limited adverse impact of breast-feeding in mothers receiving extended care for HIV-1 infection.

Figure 1

Flow chart outlining maternal follow-up from pregnancy to 2 years postpartum

Figure 2

Spline models of CD4 cell counts (A), HIV-1 RNA levels (B), and body mass index (BMI) (C) during 2 years of follow-up. Solid bold lines indicate summary data from spline models for breast-feeding and non–breast-feeding mothers, and faint lines indicate the change in the parameter for each woman.

Figure 3

Linear mixed-effects models of CD4 cell count (A), HIV-1 RNA level (B), and body mass index (BMI) (C) during 2 years of follow-up among current breast-feeders, former breast-feeders, and never breast-feeders. Differences between the current and never breast-feeders were significant for CD4 cell count and BMI decline.

Figure 4

Survival analysis comparing ever breast-feeders (EB) and never breast-feeders (NB) with respect to time to death (A), time to death or highly active antiretroviral therapy (HAART) initiation (B), and time to CD4 cell count <200 cells/µL (C). Solid lines indicate survival plots, and faint lines indicate 95% confidence intervals.