Do exclusively breast fed infants need fluid supplementation?

Exclusive breast feeding in developing countries is used by women for a very short period. The major reason given for supplementation with other fluid is the maintenance of water homeostasis. Theoretically, 80-100 ml/kg is the average daily fluid requirement for the first week; between 3-6 months, the need is for 140-160 ml/kg. the need varies with concentration of the feeds, energy consumption, activity, rate of growth, and environmental temperature and humidity. Because breast milk has a low concentration of sodium, chloride, potassium, and nitrogen only a small amount of fluid intake is needed for excretory functions. Almroth's model of basic fluid needs for a Western 4-month-old male infant are used to calculate fluid requirements; the results indicate that an exclusively breast fed infant in a hot climate would not need additional water. Estimates for an Indian infant weighing 5.5 kg at 4 months support these findings. Other scientific findings are reviewed based on clinical evidence; the risks associated with supplementation and the role of medical personnel in encouraging supplementation are also discussed. Evidence from a survey of 70 physicians and 34 nurses revealed that all considered breast milk superior to bottle feeding. 97% of nurses and 63% of doctors thought that water supplementation was necessary during the summer. The volume recommended by nurses was 180-240 ml, which was almost twice the amount recommended by doctors. Nurses recommended supplementation 1-24 times a day, while doctors suggested adopting it 2-10 times a day. There were 6 studies which tested the validity of water need based on different methodologies: Almroth (2 studies), Armelini, Goldberg, Brown, and Sachdev. Hydration was measured by specific gravity or osmolality in 4 reports, and 2 others considered breast milk intakes and urine output. One study compared exclusive breast feeding with a control receiving water supplementation. The conclusion is that water supplementation in the first 6 months is not necessary and should be actively discouraged. The education of the general public and health personnel is urgently needed. Supplementation is associated with health risks such as diarrheal morbidity or mortality, decreased milk intake, and early stops to breast feeding.