Combination feeding, also called mixed feeding, means your baby has some breastfeeds and some bottles of formula, expressed breast milk or both. It can work well for months. The key is that breast milk is made on demand: the Australian Breastfeeding Association's mixed feeding guide says the more formula your baby takes, the less milk your breasts will make.
So if you want to keep breastfeeding alongside bottles, offer the breast first, keep top-ups small and consistent, express when a bottle replaces a breastfeed, and make changes one feed at a time. If you can, the NHS suggests breastfeeding only for the first 6 to 8 weeks before bottles start. This guide covers each of those steps, how to introduce the bottle, and two example days.
Why do families combination feed?
The NHS introduction to mixed feeding lists common reasons:
- sharing feeds with a partner or family
- mainly breastfeeding but wanting the option of a bottle
- returning to work or study
- struggling with breastfeeding and needing some formula
- bottle feeding at first and then wanting to breastfeed
The Australian Breastfeeding Association notes that some parents start because of top-ups suggested in the early days, and others choose to replace certain breastfeeds. Either way, it's a valid way to feed your baby.
When is the best time to start combination feeding?
| Source | Suggested timing for the first bottles |
|---|---|
| NHS (UK) | After 6 to 8 weeks of breastfeeding only, if possible |
| La Leche League | At least 3 to 4 weeks old and breastfeeding well, unless needed sooner |
The NHS explains that breastfeeding only at first helps stimulate milk production and gives you both time to get the hang of it. La Leche League's guide to feeding breast milk other than at the breast gives a slightly earlier window.
If your midwife, GP or paediatrician has advised top-ups because of your baby's weight or feeding, follow that plan. Early top-ups don't have to mean the end of breastfeeding, and an infant feeding specialist can help you protect your supply.
How do you protect your breast milk supply when mixed feeding?
- Offer the breast first. The Australian Breastfeeding Association suggests offering both breasts, then both again after a short break, before any top-up.
- Keep top-ups small if you're worried about supply. You can always offer more.
- Express when a bottle replaces a breastfeed. The NHS suggests expressing regularly between bottle feeds to keep your supply up. See pumping basics.
- Be consistent about which feeds are bottles and how much formula you give, so your body can adjust.
- Offer extra breastfeeds if your baby seems hungry at other times.
- Pace every bottle. Paced bottle feeding helps your baby take only what they need and keeps breastfeeding appealing. The Australian Breastfeeding Association notes some babies come to prefer the bottle, which can lead to breast refusal.
- Change things gradually. If you're cutting down breastfeeds, the NHS says do it gradually to lower the risk of mastitis.
If your supply is a worry, a child-health nurse or lactation consultant can help you work out how much formula to offer so supply doesn't drop further. For ways to build supply back up, see milk supply.
Which feeds should you swap for a bottle?
There's no rule about which feed to replace. What matters most, according to the Australian Breastfeeding Association, is consistency. Some practical patterns families use:
- One regular partner feed, such as an evening feed, so the breastfeeding parent can rest.
- Bottles while apart (work, study, appointments), with breastfeeds whenever you're together.
- Small top-ups after breastfeeds when advised for weight gain.
Swap one feed at a time, and give your body a few days to adjust before swapping another. If your breasts feel uncomfortably full, express just enough to feel comfortable.
How do you introduce a bottle to a breastfed baby?
- Choose a calm moment. The NHS and the CDC's guide to bottle feeding both suggest a time when your baby is calm and not too hungry.
- Start with a small amount and offer more if your baby still shows hunger cues.
- Use a slow-flow teat to mimic the flow of breastfeeding, as the NHS suggests.
- Try someone else. The CDC says a breastfed baby may take a bottle more readily from someone other than the breastfeeding parent.
- Hold your baby close, and copy a position you use for breastfeeding.
- Give it time. The NHS says it may take a while for your baby to get used to a new way of feeding.
If your baby won't take a bottle at all, see bottle refusal. Some families use an open cup, spoon or a supply line at the breast instead; La Leche League lists these as alternatives.
What does a combination-feeding day look like?
These are fictional examples to show the shape of a day. Your baby's times and number of feeds will differ, and amounts depend on age and appetite (see how much formula).
Example day — adjust to your baby (one evening bottle at around 10 weeks)
| Time | What happens |
|---|---|
| 6:00 am | Breastfeed |
| 9:00 am | Breastfeed |
| 12:00 pm | Breastfeed |
| 3:00 pm | Breastfeed |
| 6:00 pm | Breastfeed |
| 9:00 pm | Partner gives a paced bottle; you express or rest |
| Overnight | Breastfeeds as your baby needs |
Example day — adjust to your baby (back at work, around 7 months)
| Time | What happens |
|---|---|
| 6:00 am | Breastfeed at home |
| 9:30 am | Bottle at childcare; you express at work if you're keeping supply up |
| 12:00 pm | Solids, then bottle at childcare |
| 3:00 pm | Bottle at childcare |
| 5:30 pm | Breastfeed after pick-up |
| Bedtime and overnight | Breastfeeds as your baby needs |
For planning feeds around work, see returning to work.
What else do combination-fed babies need?
Safe formula. Make formula exactly as the label says, with the right water for where you live; see preparing formula.
Vitamin D. Advice differs by country, and it depends on how much formula your baby drinks. The NHS guide to vitamins for children gives breastfed babies a daily vitamin D supplement from birth, but says babies having more than 500 mL of formula a day shouldn't have extra vitamins. The AAP's vitamin D and iron guidance recommends vitamin D for all babies unless they drink more than 27 oz (about 800 mL) of formula a day. The AAP also recommends iron supplements for partly breastfed babies from 4 months until iron-rich foods start. Ask your GP, child-health nurse or pharmacist which product to use, and see vitamin D.
When should you get help?
These signs come from the NHS guide to spotting a seriously ill baby.
Get urgent advice the same day (your GP or a health advice line (Pregnancy, Birth and Baby on 1800 882 436 in Australia, NHS 111 in the UK, your pediatrician's after-hours line in the US)) if your baby isn't feeding, is having far fewer wet nappies than usual, or keeps vomiting.
Talk to your GP, child-health nurse or a lactation consultant soon if your baby is gaining slowly, refuses the breast after bottles start, or you're unsure how much formula to give. For your own health, see your GP if a breast becomes red, hard or painful (see mastitis). For breastfeeding support, contact a breastfeeding helpline (the Australian Breastfeeding Association on 1800 686 268 in Australia, the National Breastfeeding Helpline on 0300 100 0212 in the UK).
What's worth noting while you mix feed?
For a week or two, note which feeds were breastfeeds and which were bottles, the amount in each bottle, wet nappies, and any expressing. Keep breastfeeds and bottle amounts separate: minutes at the breast and millilitres in a bottle can't be added together. A short record like this makes it much easier for a child-health nurse or lactation consultant to help you adjust the plan.
