THURSDAY, May 24, 2001 (HealthDayNews) -- In a finding that left maternal health experts scratching their heads, researchers say HIV-infected mothers who nurse are more likely to die over the short run than those who give their babies formula.
The study of women in Kenya found that those who breast-fed were about three times more likely to die of AIDS or complications of HIV within two years of delivery than those who bottle-fed their infants.
Why that is isn't clear, though it might be linked to the energy demands associated with breast-feeding, the researchers say. The number of deaths in the study was small: 18 in the breast-feeding group, six in the formula feeders. And the study, which appears in the May 26 issue of The Lancet, was designed to look at HIV transmission between mother and child, not maternal mortality.
But Dr. Ruth Lawrence, a breast-feeding specialist at the University of Rochester in New York, says the finding "strongly suggests that a prospective study looking at this might be arranged."
However, Lawrence adds, "it would be a great tragedy to take from this particular study the message that mothers shouldn't breast-feed in this circumstance. Overall, breast-fed babies do much better than bottle-fed babies, and particularly so in these high-risk countries in the world.
"The answer," continues Lawrence, "may be that, instead of spending money on formula, you spend money on nourishing the mother. Then both mother and baby do better." Breast-feeding boosts a newborn's immune system and promotes healthy cognitive and physical development.
The study followed 425 Kenyan women with HIV who got prenatal care at four Nairobi hospitals between 1992 and 1997. Half were told to breast-feed exclusively, while half were instructed to use infant formula.
Although the study lasted for two years, differences in death rates between the two groups of women cropped up within six months, the researchers say.
Twenty of the 24 women who died, or 83 percent, died of AIDS or illness related to HIV infection, the researchers say. Cause of death for the rest could not be established. Babies whose mothers died were also much more likely to die, the researchers say: 11 infants from the 24 mothers who died also did not survive.
One explanation for the difference in mortality rates could be that breast-feeding saps a mother's energy, the researchers say. Nursing is calorie-intensive, and nursing mothers tended to lose more weight than those who fed their infants formula. And, in turn, those who lost more weight were significantly more likely to die in the study.
"Thus, the excess weight loss in the breast-feeding group might have contributed to mortality," the researchers write. "However, the association between breast-feeding and maternal death persisted after controlling for weight loss during follow-up, suggesting that weight loss does not fully account for this association."
But in an editorial accompanying the journal article, Dr. Marie-Louise Newell, a pediatric epidemiologist at the Institute of Child Health in London, says the Kenya study is "unlikely" to prove real.
"I find it difficult to imagine how this would work, and I think that other studies would not confirm this if the analysis was taking into account the HIV status of the mother and the care the mother got for her morbidity," Newell says.
Not only did the nursing mothers have higher HIV loads before delivery, but because the formula group was in essence a treatment arm of the trial, those who received formula may have been more likely to return for follow-up care, Newell says.
What's more, the results from Kenya contradict an earlier report from South Africa that showed no connection between the method of feeding infants and a mother's risk of death. Yet in that trial, women who breast-fed did so exclusively, while those in the Kenya study often mixed nursing with formula feeding. "You would have expected that exclusive breast-feeding was even more draining [nutritionally] than mixed feeding," she says.
Still, if the finding does hold up through additional research, it could have a major impact on nursing guidelines for HIV-infected mothers, Newell admits. The World Health Organization now recommends that women with the AIDS virus who can safely and economically use formula should do so, but that those who cannot should breast-feed for the first four to six months after birth.
The transmission rate of HIV through breast milk is about 16 percent over a 12-month period, Newell says.
What To Do
For more on HIV, try the University of California at San Francisco or UNAIDS.
To learn more about the benefits of breast-feeding, visit Jane's Breastfeeding & Childbirth Resources. You can also try the National Library of Medicine or the University of Michigan.
If you or a loved one have HIV, visit Veritas Medicine to learn about clinical trials.
