I am breastfeeding my newborn baby. She is a Board Certified Lactation Consultant, as well as a retired La Leche League Leader. Feeding of water to newborns is not recommended.
Water fills a baby up with absolutely no nutrition.
Rapid brain growth is taking place at this time in a baby's life, so it really isn't wise to be feeding a baby empty calories. It also takes away from important time spent at the breast, and frequent supplementation in a newborn may permanently decrease a mother's milk supply. A recent study involving 1677 mothers and babies found that although 25 percent of the mothers surveyed offered their babies water, this type of supplementation is unnecessary, and may be dangerous to an infant, especially one under four weeks of age. Water supplementation in an infant can lead to oral water intoxication. When this happens, the sodium in his bloodstream becomes so diluted that the baby's body is unable to function properly.