Weaning from breast to cup depends on your baby's need to suck and his ability to drink from a cup. A baby is usually willing to wean between 9 and 18 months. If your baby is less than 9 months old, you should wean him to a bottle first. When your baby is 6 months old, you can start giving a cup, but wait to completely wean your baby until he is about 9 months old.
You can put breast milk that you have pumped and stored in the cup. You can also use formula in the cup. If your baby is over 12 months you can use regular whole milk.
If you use formula:
Plan ahead and give yourself and your baby plenty of time. Gradual weaning gives your baby time to adjust. It also allows your milk supply to diminish gradually and saves you from engorged breasts. Some mothers experience a mild depression when weaning as a result of changes in hormones related to their milk production. This is especially likely to happen if the weaning is done quickly.
Slowly increase the amount of milk your baby takes from the cup. When your baby is taking 3 to 4 oz. of milk from the cup, you can stop a breast-feeding session (usually breakfast or lunch).
If your baby is taking a daily total of 16 to 20 oz. of milk by cup, in addition to 3 meals of solid food, he can be considered successfully weaned.
If your breasts become engorged because you are no nursing as much, allow your baby to suck 15 to 30 seconds from each breast to relieve your discomfort. Make sure that you don't nurse any longer, however, or you will trigger your breasts to produce more milk--and the engorgement will get worse.
Setbacks in weaning can be caused by many things, including stress, major changes in meal or bed times, or illness. If such setbacks occur, wait until the situation improves or the illness is over, and then continue the weaning process. Call your baby's doctor if you have any questions or concerns.