Expressing breast milk, that is removing breast milk by hand or by pump to feed an infant, is very common in high-income countries. In the two weeks after giving birth to their baby, 62% of Australian mums had expressed at least some breast milk. Many Australian mums prefer to use an electric breast pump after their milk has come in, and common reasons they express are so they can go out and leave their baby with family or carers, to store extra milk, to manage their over or under supply, or because their baby has trouble breastfeeding.