How To Combine Formula and Breast Milk

Feeding your baby is one of the most important things you can do for them. There are several options, and there isn’t a one-size-fits-all for everyone. Some parents must combine formula with their breast milk, and this article will teach you how to do that safely and effectively!

Some new parents may wonder how to combine formula and breast milk – and if it’s an option.

The good news is—yes, you can feed your family both breast milk and formula if that’s what works for your family, but you do need to do it safely.

Before you proceed, please get in touch with your medical provider or a lactation consultant to ensure you are doing what’s best for your child and devise a plan to ensure your milk supply stays strong. Our team of virtual lactation consultants would love to help you—click here to learn more.

There are a few options when it comes to combining formula and breast milk that I’ll discuss in this article:

• Combining breast milk and prepared formula in the same bottle
• Feeding formula and breast milk separately
• Adding formula powder directly into breast milk

And for even more bottle-feeding and breastfeeding advice, join me in Fuss-Free First Year where you’ll find tons of resources for navigating common (and not-so-common) breastfeeding issues.

Combining breast milk and prepared formula in the same bottle

Here are the steps for combining breast milk and prepared formula in the same bottle:

1. Prepare the formula according to the instructions on the can. You should not use breast milk as the liquid – only use water.
2. Warm your breast milk.
3. Combine the breast milk and formula in the same bottle. You can do half and half, 1/4 and 3/4, or any combination you want.
4. Any breast milk combined with formula must be discarded within an hour of preparing the bottle. It cannot be fed again.

If you use ready-made formula, add it directly to breast milk. However, it is essential that you prepare a powered formula first and then add it to the breast milk. This ensures that everything is mixed correctly, and you won’t have to worry about either substance losing nutrients or becoming diluted.

Be aware that some babies may resist the combination of breast milk and formula. You may need to try different proportions or temperatures to see what works best. If your baby is refusing the bottle altogether, be sure to try out some of these bottle-refusal strategies.

Feeding Formula and Breast Milk Separately

Another method for providing formula and breast milk is in separate bottles. You could do this in the same bottle (a bottle with breast milk and then formula in another for the remainder of the feed), but most parents find this a little cumbersome and alternate between formula and breast milk bottle feeds.

There aren’t many instructions for this beyond following the proper handling of breast milk recommendations and formula preparation guidelines.

If you are giving a bottle—whether it has formula or breast milk in it—you should pump around the same time to ensure your breast milk supply doesn’t drop.

More articles you might enjoy:

• Expressed Breast Milk Calculator for Bottles
• Breastfeeding vs Bottle Feeding: Pros and Cons
• Breastfeeding with Bottle Feeding 101

Adding Formula Powder Directly into Breast Milk

This is a method sometimes referred to as “fortifying.” It is done to increase the caloric content of a bottle of breast milk from anywhere from 22 to 28 calories per ounce. Typically, this is recommended by pediatricians for low birth weight, premature, or failure-to-thrive infants.

I wouldn’t recommend this without working with a medical provider, especially because it’s typically just used with at-risk babies. It’s not my favorite option for increasing calories either way—especially for medically fragile babies—because you won’t be able to heat the breast milk to a high enough temperature to kill potential bacterial contamination in the bottle. However, pediatricians commonly recommend it.

I hope that this helped help you navigate using formula and breast milk together! Always remember to paced bottle feed your baby for the best results.

More Articles You May Enjoy:

• 12 Tips for Overcoming Bottle Refusal in Breastfed Babies
• Two Simple Ways to Scald Breast Milk to Fix High Lipase
• How to Increase Breast Milk Supply Fast: 11 Expert Tips