Expressing can increase a mother's low milk supply. Breasts respond to milk removal. If more milk is removed from the breast, more is produced. If less milk is removed, less is produced. This relationship is referred to as “supply and demand”. Expressing after breastfeeding removes more milk.
Expressing to increase the milk supply can be especially helpful in the following situations.
1) To limit the time that supplements are needed
Breastfeeding normally at each feed and slowly reducing supplements can stimulate the breast to make more milk. Expressing after breastfeeding can provide further stimulation and increase the rate at which supplements are reduced.
2) To decrease the risk of breast reluctance or rejection
If mothers have a low or very low milk supply, the baby may not be willing to breastfeed long enough to stimulate milk production. The baby may even reject the breast if the milk supply is not quickly increased. This may happen when:
- A mother’s milk appears to be coming in late and the milk supply needs to be quickly established.
- A mother’s milk supply is significantly reduced and a large part of the baby’s milk is infant formula.
- The mother is resuming breastfeeding after stopping.
- The baby is becoming more reluctant to breastfeed or has breastfeeds that are too short.
For example, a mother may be told to start supplementing a baby with infant formula because the baby had low blood sugar levels for the first few hours after birth. If the baby and mother are otherwise healthy, the mother had good milk signs, and the baby can breastfeed effectively, such supplements are rarely needed beyond this time but can be continued in error. Supplement amounts also tend to increase so that at one month such a baby may be breastfeeding and receiving an additional 600 millilitres (20 U.S. fluid ounces) of infant formula. Such a mother may benefit from expressing after breastfeeding to increase her milk supply as she slowly decreases the amount of supplement.
A tube-at-the-breast system is another way to lower the risk of breast rejection and increase the milk supply.
3) To establish the mother's milk supply
It is reasonable to express after effective breastfeeding to establish the milk supply if the mother is at risk of a low milk supply.