Canadian Task Force on Preventive Health Care

Breast Feeding

Prepared by Elaine E.L. Wang, MD, CM, FRCPC, Department of Pediatrics, University of Toronto

Objective
To assess the benefits of breast feeding and to make recommendations for encouraging Canadian women to breast feed their infants.

Burden of Suffering
For the purpose of this paper, breast-feeding refers to exclusive breast-feeding unless otherwise stated. Rates of breast-feeding in one-week-old infants in the U.S. increased from 29% in 1955 to 52% in 1989. This increase, however, reached a peak in 1982 when 62% of infants were breast fed at age one week. This pattern is matched by rates of breast-feeding at 5-6 months, which rose from 5% in 1971 to 28% in 1984 and fell to 18% in 1989. Certain groups are at greater risk of not breast-feeding, including young mothers and those in lower socioeconomic groups, particularly those receiving social insurance benefits.

Options
Interventions to encourage breast feeding include breast feeding classes, individual teaching, nursing immediately after delivery (early contact), avoidance of bottle supplementation, and avoidance of provision of infant formula samples at birth.

Outcomes
Gastrointestinal and respiratory infections, otitis media, atopic disease, diabetes mellitus, infant body weight, maternal bonding, and duration of breast feeding.

Evidence
MEDLINE was searched up to December 1993 with the terms breast feeding, counselling, infections, allergy, nutrition, and infant development, Bibliographies of relevant papers were also checked. Studies with clinical outcomes that evaluated mothers and children in developed countries were selected.

Values
The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs
One systematic review from 1986 found no differences in infections in participants in developed countries for any outcomes measured. Since then, one British cohort study found fewer gastrointestinal and respiratory infections in breast-fed infants. One Danish study found no differences, and a third cohort study found that infants who were exclusively breast fed for 4 or more months were protected against acute (odds ratio [OR] 0.72) and recurrent otitis media (OR 0.54).

Several cohort studies and 1 RCT found no increase in length of time to development of atopy in preterm infants although one study found infants who were at risk for atopy (positive family history or positive cord blood for immunoglobulin E) were protected with breast feeding. Dietary restrictions for the mother may also protect against atopy in infants who are breast fed (1 cohort and 2 trials).

Case-control studies have shown breast feeding protects against the development of diabetes mellitus, particularly in persons who have genetic markers for the development of diabetes.

Growth and development are not affected by breast feeding although some studies show lower body weight and higher intelligence in infants who were breast fed.

Studies of maternal bonding provide inconclusive data on the importance of breast feeding.

One meta-analysis (2 RCTs) of breast feeding education showed higher rates of breast feeding with education. An RCT found individual teaching was more effective than group teaching for increasing the rates of breast feeding. Postnatal support reduced the OR to 0.75 (95% CI 0.62 to 0.91) for stopping breast feeding. 1 RCT of early contact found breast feeding to be a median of 77 days longer when early contact occurred. A small Canadian study found early contact increased the rate of breast feeding continuation (60% vs 20%, P < 0.001) at the end of the study. 2 other studies had mixed results although a meta-analysis showed an overall increase in breast feeding with early contact.

Bottle supplementation studies are difficult to interpret. 2 RCTs found free samples distributed during hospital stay decreased the rate of breast feeding at 2 or 3 months.

Recommendations
Recommendation grade [A, B, C, D, E] and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

There is good evidence to counsel women to breast feed their infants [A, II-2].
There is good evidence to implement peripartum interventions (early, frequent mother-infant contact; rooming in; and banning provision of free formula samples) that promote breast feeding [A, I].

Validation
This report was externally peer reviewed. The American Academy of Pediatrics and the Canadian Pediatrics Society recommend breast feeding as the preferred method of infant feeding, and encourage public education programs, promotion of breast feeding at prenatal visits and during maternity ward care, and provision of facilities to allow breast feeding at work and day care centres. The World Health Organization and the UNICEF encourage breast feeding and support the above mentioned programs.

Sponsors
The Canadian Task Force on Preventive Health Care developed this guideline with funding from Health Canada.

Source Document
Wang E.E.L. Breast feeding. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 232-42.