Elsevier

The Lancet

Volume 355, Issue 9202, 5 February 2000, Pages 451-455
The Lancet

Articles
Effect of breastfeeding on infant and child mortality due to infectious diseases in less developed countries: a pooled analysis

https://doi.org/10.1016/S0140-6736(00)82011-5Get rights and content

Summary

Background

The debate on breastfeeding in areas of high HIV prevalence has led to the development of simulation models that attempt to assess the risks and benefits associated with breastfeeding. An essential element of these simulations is the extent to which breastfeeding protects against infant and child mortality; however, few studies are available on this topic. We did a pooled analysis of studies that assessed the effect of not breastfeeding on the risk of death due to infectious diseases.

Methods

Studies were identified through consultations with experts in international health, and from a MEDLINE search for 1980–98. Using meta-analytical techniques, we assessed the protective effect of breastfeeding according to the age and sex of the infant, the cause of death, and the educational status of the mother.

Findings

We identified eight studies, data from six of which were available (from Brazil, The Gambia, Ghana, Pakistan, the Philippines, and Senegal). These studies provided information on 1223 deaths of children under two years of age. In the African studies, virtually all babies were breastfed well into the second year of life, making it impossible to include them in the analyses of infant mortality. On the basis of the other three studies, protection provided by breastmilk declined steadily with age during infancy (pooled odds ratios: 5·8 [95% Cl 3·4–9·8] for infants <2 months of age, 4·1 [2·7–6·4] for 2–3-month-olds, 2·6 [1·6–3·9] for 4–5-month-olds, 1·8 [1·2–2·8] for 6–8-month-olds, and 1·4 [0·8–2·6] for 9–11-month-olds). In the first 6 months of life, protection against diarrhoea was substantially greater (odds ratio 6·1 [4·1–9·0]) than against deaths due to acute respiratory infections (2·4 [1·6–3·5]). However, for infants aged 6–11 months, similar levels of protection were observed (1·9 [1·2–3·1] and 2·5 [1·4–4·6], respectively). For second-year deaths, the pooled odds ratios from five studies ranged between 1·6 and 2·1. Protection was highest when maternal education was low.

Interpretation

These results may help shape policy decisions about feeding choices in the face of the HIV epidemic. Of particular relevance is the need to account for declining levels of protection with age in infancy, the continued protection afforded during the second year of life, and the question of the safety of breastmilk substitutes in families of low socioeconomic status.

Introduction

The recognition that HIV is transmitted through breastmilk raised the important question of whether strategies that promote breastfeeding in areas of high HIV prevalence should be changed.1 This policy decision is particularly difficult, given that breastfeeding provides important protection against infectious diseases,2, 3, 4, 5, 6 which account for over two-thirds of the 12 million annual deaths in children younger than 5 years in less developed countries.7

Theoretical models have been developed to assess the advantages and disadvantages of breastfeeding for HIV-positive women, as well as for women of unknown HIV status who live in areas of high HIV prevalence.8, 9, 10, 12, 13 These models have taken into account the risk of transmission through breastfeeding with regard to the age of the infant, the protection afforded by breastmilk against infectious disease mortality, the underlying HIV prevalence, and the rate of infant and child mortality. However, according to a recent WHO/UNAIDS review,14 an important limitation of these models was the poor quantification of the relative risks for mortality associated with lack of breastfeeding. Such models used relative risk estimates ranging from 1·3 to 7·9, and no model allowed for variable levels of protection within the first year of life. We did a comprehensive pooled analysis of existing studies of the effect of not breastfeeding on risk of infant and child mortality due to infectious diseases.

Section snippets

Methods

Through consultations with experts in international health, the Division of Child and Adolescent Health (WHO, Geneva, Switzerland) obtained a list of published and unpublished datasets that might provide information on the risk of infant and childhood mortality according to feeding practices. The search was limited to studies carried out in the 1980s and 1990s, to those that provided data on deaths in the first year of life (and if possible on second-year deaths as well), and to those in which

Results

We identified eight studies that met our criteria; data were obtainable from six of them.18, 19, 20, 21, 22, 23 Of those we could not obtain, one dataset had been destroyed, and the author of the other failed to respond to repeated attempts to contact him. The studies were all done between 1983 and 1991, and covered both urban and rural areas (table 1). table 2 shows the number of deaths by age, excluding deaths in the first week of life and non-infectious deaths. All studies except those from

Discussion

This paper presents the findings from a comprehensive attempt to obtain available data on all studies on cause-specific mortality according to breastfeeding. A large number of investigators were contacted by WHO, and datasets from those willing and able to participate were included. Nevertheless, only three datasets provided information on deaths in the first year of life, and six provided data on deaths in the second year. Also, we have not been able to rule out publication bias, which is

References (45)

  • HuDJ et al.

    HIV infection and breastfeeding: policy implications through a decision analysis model

    AIDS

    (1992)
  • Del FanteP et al.

    HIV, breastfeeding and under-5 mortality: modelling the impact of policy decisions for or against breastfeeding

    J Trop Med Hyg

    (1993)
  • NicollA et al.

    Infant feeding policy and practice in the presence of HIV-1 infection

    AIDS

    (1995)
  • KhunL

    Infant survival, HIV infection and feeding alternatives in less developed countries

    Am J Public Health

    (1997)
  • NduatiR

    HIV and infant feeding: a review of HIV transmission through breastfeeding

    (1998)
  • Collaborative Group on Hormonal Factors in Breast Cancer

    Breast cancer and hormonal contraceptives: collaborative reanalysis of individual data on 53 297 women with breast cancer and 100 239 women without breast cancer from 54 epidemiological studies

    Lancet

    (1996)
  • VictoraCG et al.

    International differences in clinical patterns of diarrhoeal deaths: a comparison of children from Brazil, Senegal, Bangladesh and India

    J Diarrhoeal Dis Res

    (1993)
  • BreslowNE et al.

    Statistical methods in cancer research, vol 1

    (1980)
  • de FranciscoA et al.

    Risk factors for mortality from acute lower respiratory tract infections in young Gambian children

    Int J Epidemiol

    (1993)
  • Ghana VAST Study Team

    Vitamin A supplementation in northern Ghana: effects on clinic attendances, hospital admissions, and child mortality

    Lancet

    (1992)
  • HansonLS et al.

    Breastfeeding is a natural contraceptive and prevents disease and death in infants, linking infant mortality and birth rates

    Acta Paediatr

    (1994)
  • YoonP et al.

    Effects of not breastfeeding on the risk of diarrhoeal and respiratory mortality in children under 2 years of age in Metro Cebu, the Philippines

    Am J Epidemiol

    (1996)
  • Cited by (863)

    View all citing articles on Scopus

    Members listed at end of paper

    View full text