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Rules For Mixing Breastmilk And Formula: Plus Tips To Succeed

Rules For Mixing Breastmilk And Formula

There are many reasons that parents choose to mix breast milk and infant formula. 

Some parents are trying to transition to powdered formula but want to ease the transition by mixing breast milk with the infant formula in the same bottle to make it easier for the baby to adjust to the taste. 

Others may be trying to conserve their breast milk stash, or perhaps they are doing their best to augment a low milk supply.

Mixing both types of milk in the same bottle can be safely done if you follow the rules for mixing breastmilk and formula. 

Read on to figure out how to safely mix powdered or concentrated formula with breastmilk in the same bottle.

The benefits of mixing formula and breastmilk

Peer-reviewed studies have indicated that combining powdered formula and breast milk can significantly reduce the likelihood of hospital readmission for an underweight newborn or a young infant showing signs of failure to thrive.

While many organizations encourage mothers to breastfeed until at least the six-month mark, this is not always possible. 

Illnesses, medical procedures, issues with milk production and supply, and postpartum depression can all work against the breastfeeding mother and make her feel like she has nowhere else to turn.

Powdered formula is nutritious, filling, and helps most babies sleep better at night. It also helps to put weight on an underweight or malnourished baby, allowing them to thrive and develop at this crucial stage of life.

Rules for mixing breastmilk and formula

When it comes to mixing breast milk and formula it is important to understand that you can keep breast milk and formula as separate feedings. 

You can nurse directly or feed your baby breastmilk from the bottle and then supplement with a bottle of powdered formula or concentrated liquid formula. 

This method of supplementing breastmilk with powdered infant formula is perfectly fine.

However, if you want to try combining formula with breast milk in the same bottle, there are a few rules.

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Mixing breast milk and formula in the same bottle

You can start with mixing breast milk and already prepared formula. 

This means that you have already added water to powdered formula or prepared concentrated liquid formula and are ready to feed. Then you would simply combine them in the same bottle. 

How much formula you use depends on your own preference. You can then give the mixed formula of both liquids to the baby.

The great thing about this is that if you are trying to transition your baby to exclusive formula feeding, they will still be able to get the taste of breast milk that they are used to and are less likely to reject the bottle.

The downside to this method is that if your baby does reject the bottle feeding you offer, you will most likely have to dump the bottle. 

Dumping breast milk down the drain is agonizing for a breastfeeding mother.

Separate feedings

If you supplement with formula feeds after the baby has breastfed or nursed, then you will have to mix formula and prepare a bottle of formula for your little one after the nursing or breast milk feeding session.

Mixing breast milk and formula

How to formula feed

Mixing formula is the same basically across the board. 

A scoop comes in the can of powdered formula, and one scoop, combined with two ounces of water, produces two ounces of formula. 

However, you can prepare as many ounces as you think your little one will consume, or start with a small two-ounce bottle and work your way up.

You can serve formula at any temperature, but most babies prefer for it to be warm. In this case, you can use a bottle warmer or heat the water to mix it. The formula powder dissolves and mixes better in warmer water than in cold water.

Water is important

When mixing formulas in one bottle, you must ensure that you use the correct type of water. All water is not created equally in this case. 

You should only ever use distilled or purified water instead of ordinary water. 

Although you may have safe drinking water, babies need water to be as clean as you can get it. You can buy “nursery water” or distilled water by the jug at most grocery stores.

It is also vital that you get the water content accurate when making a bottle of formula. 

Never try to make the formula stretch further by watering it down. Parents who do this ask for trouble, as they risk their babies’ health.

Combination feeding in different bottles

Combination feeding is using breastmilk and formula as your feeding method. You can do it as described above in a single bottle, but you can also do it separately.

The upside to this is that if you have been exclusively breastfeeding, your little one will get far more breast milk than formula, and if your supply is really low at this point, at least they will begin with breast milk.

You also have the benefit of knowing that you won’t have to toss out any breast milk since it is being fed to the baby first. No one wants to waste food, but when given the option of either breast milk or formula going down the drain, save the breast milk.

The downside to this method is that breastmilk has been the only taste they know for your baby, and they may reject the bottle due to the taste of formula, which is far less sweet than breast milk. 

Also, if you pump rather than nurse, you’ll have two dirty bottles to clean instead of the one that you’d have in the first method.

Dedicated formula-fed sessions

If your milk supply is dwindling, along with your milk production, you may not have the opportunity to stick with the option to breastfeed exclusively. Or perhaps you want to wean your baby off breast milk in favor of formula.

A baby’s health can suffer from rejected bottles and the effort of trying to get the baby to accept this new food. 

A baby’s body depends upon the nutrition found in warm milk, whether breast milk or formula. So if your baby hasn’t handled the transition well and is losing weight or isn’t consuming enough milk, a formula-fed session is an option.

Instead of combining breastmilk with formula or chasing breast milk with formula, you dedicate one feeding daily to formula only. You do this until your baby seems to understand the routine. Then you can increase the number of formula feedings per day.

Only do this if you are sure that you have enough breastmilk to make it work.

How long is the formula suitable for after mixing?

When supplementing with formula, it’s crucial not only to know how to prepare the milk but also to know the shelf life of the prepared formula.

Safety guidelines should always be met and followed. 

According to the Centers for Disease Control and Prevention (CDC), a prepared and mixed formula your baby has not started on is good in the refrigerator for up to 24 hours.

If you have given a bottle of the prepared formula using distilled water (never tap water), and the baby has begun to feed from it, it must be either consumed or thrown away within one hour. 

The timing is different on a bottle that has been fed because even a single drop of saliva can contaminate the bottle and start to grow bacteria.

Safety considerations should always be taken no matter your feeding method: nursing, exclusively pumping, combination feeding with formula and breast milk, or bottle feeding. 

Many parents make the mistake of thinking that the rules are the same for formula and breastmilk, which can be detrimental to your baby’s health.

Rules For Mixing Breastmilk And Formula, breast milk and formula

More tips

When you mix breast milk and formula for your baby, you may wonder if you need to add any water to the breast milk because you add water to formula, and breastfeeding yields thicker and creamier milk.

The answer here is no. Never add water to breast milk.

You can absolutely mix breast milk and formula together in a single bottle. However, if you do this, try not to make more than what you think your baby will actually consume.

Continuing breastfeeding for as long as possible will benefit your baby from the antibodies and nutrients found in breastmilk. 

While formula and breastmilk have essential nutritional value, breastmilk is full of antibodies, and its nutritional value will evolve to suit your child’s specific needs, whereas formula cannot.

Supplementing with formula

There is nothing wrong with supplementing your child’s breastmilk diet with formula. 

Feed your baby both, and don’t feel bad about it. Supplementing is done for all sorts of reasons. If supplementing with formula is what keeps your baby well fed, then do it!

As long as your little one gets the correct amount of food to aid in proper development, there’s nothing wrong with your feeding method.

If you are supplementing or feeding a combination of breastmilk and formula and would like to increase your supply, contact a lactation consultant to find out how to do that. 

A lactation consultant will listen to your concerns and provide ideas that may be able to get your milk supply back up, such as power pumping, lactation teas, and cookies, better hydration, more rest, or a healthier diet.

Whether you breastfeed and are thinking of transitioning, you breastfeed and want to supplement with infant formula due to low supply, or you want to stretch your freezer stash of breastmilk for a while, we hope you found this article helpful. 

Remember that things often seem more complicated. But at the end of the day, do what you think is best to feed your baby.

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