Going Back to Work - Your Work And Your Life - Workplace Health

With some advance planning, you can continue to breastfeed after you return to work.

To get breastfeeding well established, take as much maternity leave as you can and breastfeed exclusively for the first three to four weeks.
Once your baby is nursing well and your milk supply is well established (about three to four weeks), introduce a bottle. An occasional bottle prepares your baby to feed from a bottle while you are at work and should not interfere with breastfeeding. Keep in mind that many breastfed babies initially refuse to take a bottle from their mother; another caregiver may have to offer the bottle.
Purchase or rent a high-quality electric breast pump. At about four weeks, you can start pumping to offer the baby an occasional bottle. At about two to three weeks before you return you may want to start storing your beast milk in the freezer. Because your volume of breast milk is highest in the morning, this will be the best time to pump (pump after one or two of the morning feeds). If your baby takes a long nap at some point during the day and your breasts are especially full, take advantage of that by doing some pumping!
Be sure to label all pumped milk with the date. Fresh pumped breast milk can be stored for up to eight days in the refrigerator, two weeks in a freezer compartment within a refrigerator, three months in a freezer with a separate door, and six months in a deep freezer. If you are going to freeze the milk, you may want to put it in a breastmilk storage bag that is easily labeled, and then put the bag inside a plastic container. Once you've thawed breastmilk, it must be used within 24 hours. Heat the milk in warm water — never microwave breast milk.
Breastfeed before you leave for work and as soon as you can after you return. Breastfeed your baby during the day if your child-care provider is near your workplace. If you can't breastfeed your baby during the day, ideally you should pump as often as your baby nurses, but this isn't always possible. Try to pump every three hours. Some mothers pump as soon as they get to work, and then at lunchtime; if you have any breaks, use them for pumping as well. If you have your own office, just lock the door and put up some sort of do not disturb sign. If you share an office, or have a job without an office, you will have to get more creative about where to pump. More and more employers are providing places for employees to pump; if your workplace doesn't have one, talk to your employer about the best solution for you. All you need is some privacy and, if you have an electric pump, a plug.
If possible, adjust your work schedule to minimize feeding times away from your baby. Work part-time, job share, or work at home part of each day or week, if possible.
Returning to work can be a very stressful time for you. Some mothers find that having the partner drop the baby off to the care provider helps reduce the difficulty of having to leave their baby.
Try to return to work on a Friday, so that you can have the weekend to regroup and rebuild your supply by nursing you baby.