vitababyIn short
Combination feeding means giving your baby both breastmilk and formula. For a slow-gaining baby it can be a way to add milk while continuing to breastfeed, often using expressed milk first and formula top-ups if needed. Because regular breastfeeding maintains your supply, introduce bottles gradually and keep breastfeeding or expressing so supply is protected. If you are combination feeding because of slow weight gain, it is worth getting feeding support from your health visitor or an infant feeding specialist so the cause is addressed too.
Key takeaways
- Combination feeding gives both breastmilk and formula, and can add milk for a slow-gaining baby.
- Introduce bottles gradually and keep breastfeeding or expressing to protect your supply.
- Expressed breastmilk can be offered before formula top-ups where possible.
- If top-ups are for slow weight gain, get feeding support so the underlying cause is addressed.
When top-ups can help
If a breastfed baby is gaining slowly, additional milk — expressed breastmilk where possible, or formula — can help them take in more while you work out and address the underlying reason. Top-ups are sometimes suggested by a health visitor or GP as a short-term support, and sometimes part of a longer-term mixed-feeding plan that suits your family.
Protecting your milk supply
Breastmilk supply responds to demand, so the more milk is removed from the breast, the more is made. If you replace breastfeeds with bottles without expressing, your supply can gradually reduce. To keep supply up while combination feeding, introduce bottles gradually, continue to breastfeed regularly, and express if you miss a feed — especially in the early weeks while supply is still establishing.
- Offer the breast first, then top up if your baby is still hungry, where that works for you.
- Use expressed breastmilk before formula when you have it.
- Introduce bottles gradually rather than all at once.
- Use paced bottle-feeding so your baby takes the bottle calmly and not too fast.
Making up formula safely
If you use formula, always make it up exactly according to the instructions on the packet — never add extra powder to “strengthen” a feed, as over-concentrated formula is unsafe for a baby’s kidneys and hydration. First infant formula is suitable for the whole first year unless your GP advises a specialist formula.
Get feeding support
If you have moved to top-ups because of slow weight gain, it is worth having feeding reviewed by your health visitor or an infant feeding specialist. Sometimes a latch or positioning change, or treating an underlying cause such as reflux or cow’s milk protein allergy, addresses the slow gain — and that may change how much topping up is needed.
VitaBaby logs breast, expressed, and formula feeds separately and charts them against the weight trend, so you can see how combination feeding is affecting gain and share a clear record at your appointment.
FAQ
Will giving formula reduce my breastmilk supply?
It can, if breastfeeds are replaced by bottles without expressing, because supply responds to how much milk is removed from the breast. Introducing bottles gradually and continuing to breastfeed or express helps protect your supply.
Can I top up a breastfed baby with formula for weight gain?
Yes, top-ups are sometimes used to support a slow-gaining baby, ideally with expressed breastmilk first and formula if needed. If it is for slow weight gain, also ask your health visitor or GP to review feeding so the cause is addressed.
How do I combine breast and bottle without confusing my baby?
Introduce bottles gradually, use paced bottle-feeding so the flow is gentle, and keep breastfeeding regularly. Many babies switch between breast and bottle without difficulty; a health visitor can help if your baby is finding it hard.