Definitions of Breastfeeding

Dear Editor:

Labbok and Starling ¹ have again raised one of the most important issues in breastfeeding and pediatric research: how to define breastfeeding in a repeatable and clinically meaningful way. They concluded that “there remains a need for increased journal attention to requiring inclusion of breastfeeding definitions and for researcher attention to their use.” In the Asia Pacific region we have found similar variations in the application of breastfeeding definitions in reviews of breastfeeding in China, Japan, and Australia, which lead to wide variation in the reported rates of breastfeeding.^2–5

Two of the major difficulties with defining “exclusive breastfeeding” are the use of a 24-hour recall methodology and the age of the infant at the time of interview (i.e., recall length). The use of 24-hour recall data may miss including many episodes of non-breastmilk feeds and lead to a wide variation in the reported rates of exclusive breastfeeding. This has important physiological consequences as prelacteal and complementary feeds may change the physiology and growth of the infant. For example, the effects of breastfeeding on the composition of the human microbiome and on obesity, to name but two areas of interest, may depend on the exclusivity of breastfeeding.^6–8

We support the need for discussion of the use of consistent definitions of breastfeeding. This also needs to include the way in which the definitions are implemented in the field to produce accurate and repeatable results. The definitions should also be related to physiological outcomes. The challenge will then be to get data collected in a standardized way on a regular basis.