Pregnant women can start wearing nursing underwear from mid-pregnancy. Mid-pregnancy due to the obvious increase in breast size, if the bra wearing discomfort will cause damage to the breast, later recovery is more difficult. Breastfeeding underwear has the following benefits: 1, to prevent breast sagging: during pregnancy under the stimulation of estrogen and progesterone, breasts will gradually increase in mid-pregnancy, the muscles on both sides of the breasts can not support the growth of the breasts and the occurrence of laxity, resulting in breast sagging. Breastfeeding underwear material is soft, not only can reduce the degree of breast sagging, but also reduce the pressure on the shoulders and back; 2, to improve the sense of comfort: along with the increase in the months of pregnancy, in the mid-pregnancy when the pregnant belly will be more and more obvious, wearing an ordinary bra will produce a sense of tightness, inhibit the growth and development of the fetus. Wearing soft fabrics, elastic nursing underwear, comfort is stronger, can avoid the fetus is affected. In addition, when you start wearing nursing underwear in mid-pregnancy, you can assist with appropriate breast massage, which is beneficial to the secretion of milk after birth. It should be noted that before the massage and before breastfeeding with a hot towel to wipe the breast, to ensure that the breast skin is clean and hygienic, to avoid cross-infection.