In this episode, we will be reviewing what you need to know before your first discussion about infant formula.  We will cover the characteristics and types of formulas, why infants might require different types, the correct way to prepare formula and how much infants need, common concerns from parents, indications for changing formulas, and when to transition away from it.

1. Reasons for formula feeding 
   1. Human milk is first choice for most infants
   2. Concern about lactating parent’s milk supply
   3. Workplace conditions make it difficult to sustain human milk feeding
   4. Parent preference 
   5. There are few true contraindications to breastfeeding. 
      1. Galactosemia
      2. Maternal HIV infection that has not achieved an undetectable viral load
      3. Maternal phencyclidine (also known as PCP) or cocaine use
      4. Active Herpes Simplex virus lesion
      5. Active tuberculosis
2. Types of formula: 3 characteristics
   1. Caloric density: calories per ounce. Standard term formula is 20 calories/oz. Infants born preterm or have growth failure may need 22-27 calories/oz.
   2. Carbohydrate source: Lactose (galactose + glucose) or non-lactose
   3. Protein type: 
      1. Cow-milk based formula proteins are whey and casein.
      2. Hydrolyzed formulas: proteins are broken down into smaller protein “chunks” or into individual amino acids, which are hypoallergenic and easily digestible. 
      3. Other formulas utilize different sources of protein, including soy protein and goat’s milk.
      4. Special formulas for infants with specific metabolic conditions: eg. phenylketonuria, maple syrup urine disease, homocystinuria.
3. Forms of formula
   1. Powder: most common and least expensive. Usually, 1 scoop of formula powder is mixed with 2 oz water. 
   2. Liquid concentrate: mixed 1:1 with water. 
   3. Ready to feed: no mixing required, but most expensive.
   4. Be sure that the formula is being mixed correctly! Incorrect formula mixing can result in growth failure or electrolyte abnormalities.
4. How much formula should be given?
   1. A good rule of thumb is that infants require between 120-150 calories/kilogram per day. 
5. Common myths about formula
   1. Lactose intolerance. True congenital lactase deficiency is rare disorder and, in infants, it will usually present with very severe diarrhea. 
      1. What adults experience as lactose intolerance occurs later in childhood. 
      2. Developmental lactase deficiency can occur in premature infants, but lasts for a short time after birth and the majority are still able to consume lactose-containing formulas. 
      3. Infants can develop a temporary, self-resolving lactase deficiency after suffering from a gastroenteritis
   2. Increased spit ups (often at around 4 months of age): Generally not a sign of formula intolerance.  
   3. Gassiness and stomach discomfort after feeding: Normal and usually not a reason to switch formulas. 
6. Medical reasons to switch formula type
   1. Galactosemia: most often diagnosed after abnormal newborn metabolic screen.  
   2. Milk protein allergy: usually presents with blood in stool from allergic proctocolitis.  Rarely, more severe milk protein allergies can present as hives or even anaphylaxis. 
   3. Metabolic disorders 
7. Usually stop infant formula at 1 year of age and switch to cow’s milk, usually whole milk. 
   1. Do not switch to cow’s milk before 1 year of age because of solute load on kidneys. 

Resources/Links:

https://www.healthychildren.org/English/ages-stages/baby/formula-feeding/Pages/default.aspx

https://www.aafp.org/pubs/afp/issues/2009/0401/p565.html

https://www.cdc.gov/nutrition/infantandtoddlernutrition/formula-feeding/choosing-an-infant-formula.html

https://kidswithfoodallergies.org/recipes-diet/nutrition-and-health/formula-options-for-kids-with-food-allergies/#:~:text=Extensively%20Hydrolyzed%20Formulas%20(e.g.%2C%20Enfamil,common%20cause%20for%20allergy%20symptoms.

Links:

https://www.healthychildren.org/English/ages-stages/baby/formula-feeding/Pages/default.aspx

About the Speaker:

Host: Paige Howard – Paige Howard completed her medical education at the University of Virginia School of Medicine. She is now a pediatric resident at Children's Hospital of Philadelphia (CHOP).

Clerkship Ready: Pediatrics is a podcast aimed at medical students doing their clinical clerkship in Pediatrics. The views expressed are the speakers' own and do not constitute medical advice.