Babies are like tiny little machines. They do a lot of growing in their first year of life, and proper nutrition is a key to their successful development. You should always mix your infant formula according to the manufacturer's instructions. Improperly mixing baby formula is associated with dangers, and failing to follow the manufacturer's instructions can cause serious health complications, illness, and even death.
Some news reports have found that budget-strained parents are often diluting infant formula in an effort to save money, according to HealthyChildren.org. This over-dilution changes the ratio of water to formula, which increases the amount of water per serving of formula and decreases the amount of formula the baby is consuming. Since formula powder contains all the nutrients an infant needs to thrive, lack of nutrients can cause slower physical growth and developmental delays, and can leave an infant vulnerable to immune deficiencies and illnesses.
Conversely, adding more formula per ounce of water than manufacturers direct can also be dangerous. This is under-dilution -- and although hospitals often do this purposefully in failure-to-thrive babies (babies who are not showing enough growth for their age) -- doctors do not recommend this for healthy infants. Under-dilution can create excessive strain on the kidneys and digestive system, which can lead to dehydration, which is dangerous for an infant.
Improper Growth and Development
Caregivers who over-dilute or under-dilute infant formula put the infant in danger of improper growth and development. Too many nutrients may cause the body internal stress while too few nutrients from under-dilution can leave the infant without vital nutrients. Adding infant cereal to an infant's bottle in addition to formula replaces the nutritionally balanced formula with additional food, and it poses a choking hazard and does not teach proper eating habits. Instead, when an infant shows signs of readiness, begin feeding complementary foods like infant cereal and other age-appropriate solids, but ask your pediatrician for recommendations on appropriate solids and feeding techniques. Signs of readiness include sitting up with support and losing the tongue-thrust reflex that causes a baby to push any food out of the mouth.
Perhaps the most serious danger of improperly mixed infant formula is that of water intoxication. Water intoxication occurs when too much water is in a baby's system. Excess water in the body can result from over-dilution or feeding additional water to a bottle-fed baby outside of regular feedings. Water intoxication disrupts baby's electrolyte balance and can cause seizures. Too much water also disrupts the sodium levels in an infant's body, which can cause seizures, coma, brain damage, and death. You should only give water given to your infant in addition to regular bottles if he has already had his bottle and he remains hungry. You should not give more than two to three ounces at a time.