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A baby drinking milk from a bottle next to a baby breastfeeding

The HSE, UNICEF, paediatricians and midwives all agree that exclusive breastfeeding, for the first six months if possible, is best.

For optimal health, exclusive breastfeeding is recommended unless your baby is receiving prescribed supplementary formula feeds due to poor growth or ‘failure to thrive’.

If you are worried about how much milk your baby is getting, it’s better for his long-term health to try and build up your milk supply rather than supplement it with formula milk. If you are concerned about your milk supply it may help if you go along to your local breastfeeding support group. See our article on common breastfeeding problems for more tips, but if you are worried about your baby’s growth, weight gain or how much milk he is getting, speak to your doctor urgently.

Risks of combined or mixed feeding

There are two main risks to switching away from purely breastfeeding that you need to bear in mind.

The effect of introducing formula milk to your baby’s gut

When colostrum (the first milk you produce) and mature breast milk enter your baby’s gut they line it with a protective layer that promotes optimal gut flora and immune health. Exclusive breastfeeding is best but the more breast milk your baby gets the greater the benefits. Formula milk interrupts this process and may allow microbes to pass across the gut lining where the protective coating from breast milk is interrupted.

The effect on your milk supply

Swapping breastfeeds for formula feeds, especially in the early weeks after birth will reduce the breast tissue that produces milk and lessen your milk supply just when it’s really important to build and establish a good supply for your baby.

This is because your breasts won’t be stimulated as much if you substitute formula feeds for breastfeeds. In turn, this means you may start producing less milk than you were before.

What if I’m returning to work?

If you’re going back to work and won’t be able to breastfeed your baby as often, switching from breastfeeding to giving your baby expressed milk or formula milk from a bottle is the only option. Read more about expressing milk by hand or pump.

Combining breastfeeding and formula feeding

You may have decided that you will partly breastfeed your baby and partly formula feed him. In this case, your milk supply will almost certainly reduce over time. It might not happen quickly as your breasts will initially still expect your baby to be breastfeeding. So you may need to express milk just to prevent your breasts from becoming hard and engorged. Be aware that if you do introduce a bottle of formula milk you will reduce the stimulation that your breasts receive.

More formula feeds

Mums sometimes find that they want to introduce just one bottle of formula but they end up increasing the number of bottles of formula that their baby receives each day. Reasons for this include:

  • A knock-on effect on their milk supply
  • Changes in their baby’s hunger and fullness patterns

Their baby sometimes refuses breastfeeds (especially if they were having problems breastfeeding) as milk drips more easily into their mouths from a bottle whereas breastfeeding uses more muscles.

Can I switch back to exclusive breastfeeding?

You may have tried formula feeding and want to switch back to breastfeeding. This is usually quite difficult, since your body has had signals to stop or reduce milk production, but it’s still quite possible. The main thing to remember is that it will take some time and it’s definitely worth persevering. Follow all the same guidelines as you did for early breastfeeding and your milk supply should build up again. Feeding little and often is the golden rule.

Is there any benefit to mixed feeding versus formula feeding?

Breastfeeding is very good for your baby. If you are going back to work he will benefit from a breastfeed before you leave for work and another feed when you get home. Depending on his age and stage, feeds at night will stimulate your supply.

The benefits of partial breastfeeding include:

  • Comfort and bonding (especially if you’ve been out at work)
  • Prevention of diseases and allergies, plus immunological benefits – the more breast milk, the greater the benefit. Even 50ml of breast milk per day will help to promote optimal health
  • Nutritional benefits – breast milk contains over 100 ingredients which cannot be produced in formula milk – even small amounts of these ingredients are great for your baby
  • Improved oral development (breastfeeding develops the facial muscles)

Will letting my partner formula-feed our baby improve their bond?

Your partner can fully bond with your baby in lots of ways, for example:

  • Skin-to-skin contact
  • Chatting during bathing and changing
  • Sharing books
  • Cuddles and carrying him in a soft sling

This means your baby can enjoy the huge benefits of breast milk and breastfeeding as well as having lots of lovely bonding time with daddy. Find more top tips for dads here.


Tesco Baby Club is closing on 17 December 2018.

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