WHO Comments On Lancet Study Reporting Higher Mortality In HIV+ Mothers.(who breastfeed their babies, World Health Organization)

2001 JUL 12 - (NewsRx Network) -- The following statement was issued in June 2001 by the World Health Organization:

A recent paper by Ruth Nduati and colleagues in the Lancet (May 26, 2001;357:1651-5; [see also the accompanying NewsRx report, also under Breastfeeding]) reported a three-fold higher mortality rate in HIV infected mothers who breastfed their infants compared with those who fed their infants with formula.

These results arose from a secondary analysis of a randomized trial of breastfeeding compared with formula feeding conducted in Nairobi, Kenya, between 1992 and 1998 (Nduati et al., JAMA, 2000;283:1167-74). The trial was designed to assess the rates of mother to child transmission of HIV according to mode of infant feeding. Eighteen of 197 women randomly allocated to breastfeed their infants died within 24 months of delivery compared with six of 200 women allocated to the formula-feeding group. The cumulative 24-month mortality rates were 11% and 4%, respectively, corresponding to a 3.2-fold higher risk of death (95% confidence interval 1.3-8.1). Since assessing mortality in mothers was not the primary objective of the trial, this unexpected observation must be interpreted cautiously. Preliminary results on mortality were communicated [by Nduati et al.] in July 2000 in Durban.

A strength of the study was the random allocation to mode of infant feeding, and the authors correctly present their primary results according to randomized group. However there was considerable noncompliance with the allocated infant feeding group (4% of those allocated breastfeeding did not give any breast milk to their infants and 29% of those allocated formula feeding also gave breast milk). Potentially useful additional information could be obtained by considering the mortality rates according to a measure of milk production, such as the proportion of daily infant feeds given as breast milk.

The authors suggest that the high energy demands of breastfeeding in HIV infected mothers may accelerate the progression to HIV related death. If this is true then a higher death rate should be apparent in women who breastfed their infants exclusively compared with those who gave their infants food supplements or avoided breastfeeding altogether.

By contrast, Coutsoudis and colleagues have published an analysis of morbidity and mortality in mothers enrolled in a randomized study of vitamin A supplementation conducted in Durban, South Africa, analyzed according to their chosen method of infant feeding (AIDS, 2001;15:653-54). This secondary analysis was conducted to specifically address the concerns raised by the preliminary results from Nduati and colleagues and showed that two of 410 (0.5%) women who ever breastfed their infants died compared with three of 156 (1.9%) who never breastfed. In addition there was no excess of any reported morbidity in mothers who breastfed compared with those who did not (12.7% and 14.7%, respectively). While these results are reassuring, the limitations of the analysis must be recognized - women chose whether or not to breastfeed their ...