Survival of infants born to HIV-positive mothers, by feeding modality, in Rakai, Uganda

Abstract

Background: Data comparing survival of formula-fed to breast-fed infants in programmatic settings are limited. We compared mortality and HIV-free of breast and formula-fed infants born to HIV-positive mothers in a program in rural, Rakai District Uganda.

Methodology/principal findings: One hundred eighty two infants born to HIV-positive mothers were followed at one, six and twelve months postpartum. Mothers were given infant-feeding counseling and allowed to make informed choices as to whether to formula-feed or breast-feed. Eligible mothers and infants received antiretroviral therapy (ART) if indicated. Mothers and their newborns received prophylaxis for prevention of mother-to-child HIV transmission (pMTCT) if they were not receiving ART. Infant HIV infection was detected by PCR (Roche Amplicor 1.5) during the follow-up visits. Kaplan Meier time-to-event methods were used to compare mortality and HIV-free survival. The adjusted hazard ratio (Adjusted HR) of infant HIV-free survival was estimated by Cox regression. Seventy-five infants (41%) were formula-fed while 107 (59%) were breast-fed. Exclusive breast-feeding was practiced by only 25% of breast-feeding women at one month postpartum. The cumulative 12-month probability of infant mortality was 18% (95% CI = 11%-29%) among the formula-fed compared to 3% (95% CI = 1%-9%) among the breast-fed infants (unadjusted hazard ratio (HR) = 6.1(95% CI = 1.7-21.4, P-value < 0.01). There were no statistically significant differentials in HIV-free survival by feeding choice (86% in the formula-fed compared to 96% in breast-fed group (Adjusted RH = 2.8[95%CI = 0.67-11.7, P-value = 0.16]

Conclusions/significance: Formula-feeding was associated with a higher risk of infant mortality than breastfeeding in this rural population. Our findings suggest that formula-feeding should be discouraged in similar African settings.

Figure 1. Consort diagram showing follow-up of infants, losses to follow-up, deaths and HIV-infection.

* Includes one new HIV-infection observed at six months for an infant who was not tested at one month. † Infection occurred by one month. Failure to be tested was a result of refusal by the mothers to have their babies tested and a minority of cases it was due to insufficiency of the infant sample.

Figure 2. Kaplan-Meier cumulative probabilities of survival from death by feeding group.

Actual visits grouped by the three scheduled visits at one, six and twelve months after birth.

Figure 3. Kaplan-Meier cumulative probabilities of HIV-free survival by feeding group.

Actual visits grouped by the three scheduled visits at one month, six months and twelve months after birth. *Adjusted for maternal age and maternal antiretroviral therapy. ** Twenty five observations left-censored for the following reasons: 12 babies were HIV-positive at one month without HIV results at birth, 9 were not tested for HIV at one month, and 4 losses to follow-up. † Three infants who were HIV-positive at one month were left-censored.