Combining Breastfeeding and Bottle-Feeding
You may choose to breastfeed and give infant formula for some of your baby's feedings. Supplementing breast milk with formula may decrease your supply of breast milk. But it will not stop your breast milk production. It is best to wait until your baby has been breastfeeding well for at least 6 weeks before offering your baby formula.
Some babies have problems transferring their sucking patterns back and forth between their mother's breast and a bottle. Sucking a bottle requires different tongue and jaw motions from those needed to breastfeed.
Sometimes the shape of the nipple plays a part in how well your breastfed baby adjusts to bottle feedings. Many types and shapes of nipples are available. It will probably take some experimenting before you find one that works well for your baby. For example, some babies may have trouble using a flat nipple—the kind that is usually attached to bottles that have plastic inner liners. Some babies are not able to suck on the breast nipple strongly enough to get breast milk. But some babies have problems with longer nipple tips because it causes them to gag during feeding. It may help to look for a type of nipple that most closely matches the shape of the mother's nipple.
For more information, see the topic Breastfeeding.