When Is It Safe To Give My Baby Water?

Breast milk or infant formula provides all the fluids your baby needs during the first year of life. If you’re concerned about your baby getting dehydrated on a hot day, don’t be. Breast milk is roughly 88 percent water, so it satisfies your baby’s fluid needs even on hot days.

The more you breastfeed, the more milk you make. By giving your baby water to quench her thirst you can actually cause your milk supply to drop. Since human milk provides not only calories and nutrients, but also protects against a wide range of illnesses, it’s always best to satisfy your baby’s thirst through breastfeeding.

Giving too much water to your baby can actually cause a rare but serious condition known as hyponatremia (read more about hyponatremia here). What is unclear is how much water is too much.

When and how to introduce water
Water lacks nutrients and calories and should never be used as a substitute for breast milk or infant formula. While it may be safe to give a baby who is already eating a wide variety of foods small sips of water in a cup, until more information is available on quantity, parents may find the following suggestions helpful:

• Wait at least six months, and until your baby is eating a variety of foods. The American Academy of Pediatrics (AAP) recommends that solid foods not be given until about 6 months of age. Until then, babies should receive only breast milk or, if that’s not possible, infant formula. Once babies are consuming a variety of foods in addition to breast milk or formula, giving your baby small sips of water in a cup is likely safe. Since there is no evidence to show a safe, upper limit, however, it is best to stick with sips of water rather than ounces of water.
• Recognize foods high in fluids. Babies who eat a variety of foods are likely getting more fluids than their parents realize. Examples of foods high in fluids include fruits, vegetables, and purees.
• Know your water source. Check with your local water supplier or go to My Water’s Fluoride to find out if your local tap water is fluoridated or contains a substantial amount of natural fluoride. If the fluoride level exceeds 0.7 parts per million (ppm) for warmer climates or 1.2 ppm for cooler climates, consider using low-fluoride or fluoride-free water when giving your baby sips of water in a cup or when mixing concentrated liquid formula or powdered formula. If the risk of fluorosis is high, parents are encouraged to use a ready-to-feed formula eliminating the need for added water. While too much fluoride can lead to fluorosis, too little fluoride can lead to tooth decay. The AAP recommends that all children between the ages of 6 months and 16 years receive fluoride supplements if local drinking water contains less than 0.3 ppm.
• Know your plumbing. Since many older homes have lead in their plumbing pipes, parents are urged to run the cold water for 15–20 seconds before putting it in your baby’s cup. Cold water picks up less lead than hot water, and running the water for several seconds ensures you’re not giving your baby the water that has been standing in the pipes, absorbing potential contaminants.
• Give water at mealtimes. Offering small amounts of water at mealtimes can ease a bottle-fed baby’s transition from the bottle to a cup and reduce the risk of tooth decay. Make sure, however, that your baby continues to eat an adequate amount of nutritious foods, since water intake can diminish appetite.
• Start small. Once your child is eating a wide variety of solid foods, you can offer your child small sips of water in a cup. And don’t be surprised if your baby gets more water on herself than in herself!
• Forgo water when your baby is sick. Sick babies are at greater risk for dehydration due to vomiting or diarrhea. Breast milk or formula can usually satisfy your baby’s fluid needs, but sometimes your baby’s health care provider will recommend an oral rehydration solution (ORS) such as Pedialyte. ORSs are designed to replace lost fluids, as well as important electrolytes such as sodium and potassium.
• Check with your baby’s health care provider. Small amounts of water are unlikely to harm your baby, but until researchers determine exactly how much water is safe, parents are encouraged to check with their baby’s pediatrician for specific recommendations based on the baby’s age, weight, and overall health.

If you are concerned that your baby is not getting adequate fluids (i.e., fewer wet diapers or signs of dehydration), contact your baby’s health care provider right away.