Merck Manual

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Formula Feeding


Deborah M. Consolini

, MD, Thomas Jefferson University Hospital

Reviewed/Revised Sep 2023

The only acceptable alternative to breastfeeding Breastfeeding (See also Nutrition in Infants.) Breast milk is the nutrition of choice for young infants. The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for a minimum of 6 months... read more during the first year is formula; water can cause hyponatremia, and whole cow’s milk is not nutritionally complete. Advantages of formula feeding include the ability to quantify the amount of nourishment and the ability of family members to participate in feedings. But all other factors being equal, these advantages are outweighed by the undisputed health benefits of breastfeeding.

Commercial infant formulas are available as powders, concentrated liquids, and prediluted (ready-to-feed) liquids; each contains vitamins, and most are supplemented with iron. Formula should be prepared with fluoridated water; oral fluoride drops (0.25 mg/day) should be given after age 6 months in areas where fluoridated water is unavailable and when using prediluted liquid formula, which is prepared with nonfluoridated water.

Choice of formula is based on infant need. Cow’s milk–based formula is the standard choice unless spitting up, diarrhea Diarrhea in Children Diarrhea is frequent loose or watery bowel movements that deviate from a child’s normal pattern. Diarrhea may be accompanied by anorexia, vomiting, acute weight loss, abdominal pain, fever,... read more (with or without blood), rash Rash in Infants and Young Children Rash is a common complaint, particularly during infancy. Most rashes are not serious. Rashes can be caused by infection (viral, fungal, or bacterial), contact with irritants, atopy, drug hypersensitivity... read more Rash in Infants and Young Children (hives), or poor weight gain suggests sensitivity to cow’s milk protein or lactose intolerance (extremely rare in neonates); then, a change in formula may be recommended. All soy formulas in the United States are lactose free, but some infants allergic to cow’s milk protein may also be allergic to soy protein; then, a hydrolyzed formula is indicated. Hydrolyzed formulas are derived from cow’s milk, but the proteins are broken down into smaller chains, making them less allergenic. True elemental formulas made from free amino acids are available for the few infants who have allergic reactions to hydrolyzed formula.

Bottle-fed infants are fed on demand, but because formula is digested more slowly than breast milk, they typically can go longer between feedings, initially every 3 to 4 hours. Initial volumes of 15 to 60 mL (0.5 to 2 ounces) can be increased gradually during the first week of life up to 90 mL (3 ounces) about 6 times/day, which supplies about 120 kcal/kg at 1 week for a 3-kg infant.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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