The specific reasons why women’s breasts become smaller after breastfeeding are as follows: 1, hormonal effects: from the beginning of pregnancy, the mother’s breasts store milk, so the breasts have been in an enlarged state. The mother began to breastfeed, breasts tend to be more plump, after the delivery of estrogen secretion is too little, thus triggering the breasts become smaller. 2, too tired: the cause of maternal breast smaller, there may be breastfeeding baby breastfeeding, with children too tired, physical exertion, body shape slowly become thin, resulting in smaller breasts. 3, corset discomfort: maternal breast smaller may also be due to bra wearing Inappropriate cause, if the bra is too small, there may be excessive squeeze on the breast, but also often may cause the breast to become smaller, so avoid wearing tight corsets.