If you find expressing breastmilk difficult or you just don't want to do it, and your baby is not yet on solid food, you will need to give your baby formula milk if you are going to be away for long. Formula milk is usually cow's milk modified to suit babies' developing digestions (Current recommendations are that you should only use soya-based formula milks on the recommendation of a health professional). The amount your baby needs will vary. It is important therefore that you make up the feeds according to the instructions on the package. You also need to take care to use the sterilising equipment accurately.
If you plan to use formula milk, it's best to start mixed feeding after your milk supply has become established. Timing can be tricky. If you introduce a bottle before your baby is skilled at breastfeeding, you may find that he or she prefers a bottle.
Introduce a bottle too late and the baby may not want any substitute for their mother's breastmilk. Your milk supply will drop if your baby starts to prefer feeding from a bottle and breastfeeds less. You can boost it by breastfeeding more often. Offer both breasts at each feed and express any remaining milk after a feed. Also try resting with your baby and letting him or her feed whenever they want. Just as when you feed less you make less milk, so feeding more will make more milk. Within a day or so, your milk supply should have increased again.
"I'm glad I managed to carry on breastfeeding after going back to work when Jack was four months. Feeding him myself when I got home was a lovely way of reconnecting with my baby."