During pregnancy, as hormone levels increase, so does blood flow and fluid retention causing your breasts to feel swollen, sore and sensitive to touch. However, every pregnant woman’s situation is different. Some may feel their breasts getting bigger after three months of pregnancy, while others may not experience a noticeable change until after five months.


Breast changes during pregnancy, postnatal & breastfeeding



  • Early pregnancy
    The first three months of pregnancy are the embryonic stage of fetal development and also the first stage of female breast development. During this time, the female breasts will start to experience swelling and pain due to hormonal change. By the third month of pregnancy, your breasts are likely to be around 1-2 bra cup sizes bigger than before pregnancy. If you do not wear a bra, your sensitive nipples may directly contact with your clothing and cause discomfort.
  • Second/ third trimester
    During the 7th to 10th month of pregnancy, as the due date approaches, the increase in hormones may promote further growth of the breasts. A sudden increase in size can cause extra loose and sagging skin, particularly around the breasts.
  • 2-3 days postnatal
    In the first few days after delivery, your breasts undergo significant changes due to the need to provide breast milk to the baby. Your mammary glands noticeably become bigger and start to produce breast milk. During this stage, your nipples become sensitive when breastfeeding.
  • 3-4 days postnatal
    The size of the breasts during postnatal depends on the amount of milk your baby needs. Typically, the breasts are most full and swollen 3-4 days after delivery,  the golden period for producing milk. During this time, it is necessary to frequently feed the baby and try to establish a mutual understanding of supply and demand between you and your baby.
  • 5-30 days postnatal
    After 5 days postpartum, you enter the lactation phase, the more milk your baby needs,  the more milk you produce. Generally, the size of the breasts reaches its peak around one month postpartum. Afterward, when a balance is established between the supply and demand with the baby, the size of the breasts will not show excessive enlargement unless you frequently remove the milk, causing an oversupply of milk, which will cause the breasts to swell due to continuous milk production stimulation.


When should I change my maternity/nursing bra?


Mummy A: Pregnant women normally have a higher body temperature, so wearing underwear is even hotter than wearing a shirt. Go braless at home is more comfortable.

Mummy B: You can buy looser ones, go one cup size bigger, it will sag if you do not wear any bras. My colleague didn’t wear bra when she was pregnant and breastfeeding, and now her breasts are saggy.

Mummy C: You must wear a bra, otherwise it’s difficult to get back your original breast shape. I regret not wearing the right bra when I was pregnant, but there’s nothing I can do now. I feel embarrassed to let my husband see my saggy breasts…

Doctors advocate that mothers should pay attention to breast care from pregnancy onwards. During the pregnancy and breastfeeding period, the breasts will increase in cup size and weight due to the filling of milk, which also increases the burden on the body. Maternity and nursing bras are designed specifically to accommodate the breasts and facilitate breastfeeding for women during this period. Besides easy to wear, nursing bras also provide the necessary support to the breasts, preventing sagging. Therefore, it is essential to wear nursing bras during the breastfeeding period.


What Happens If You Are Not Wearing A Right Nursing Bra?


Harm 1: Causing breast pain
During pregnancy, the enlargement of the breasts begins from the lower portion. If a dedicated maternity bra is not worn during pregnancy, the breasts may experience compression and stretching, causing discomfort for expectant mothers.


Harm 2: After delivery, there is a risk of insufficient or low milk supply

The skin around the breasts becomes particularly sensitive during pregnancy, you must take care not to put pressure on the growth and development of the mammary glands. Please take note that the uncomfortable fabric of the bra may cause friction against the skin, which may affect milk production.

Harm 3: Causes breast deformity

During pregnancy, the continuous enlargement of the breasts may increase the risk of sagging. Regular bras are not able to effectively protect and support the breasts of pregnant mothers and may cause deformity and sagging. If the bras are too small, auxiliary breast tissue may appear, while if they are too large, they can result in breast sagging.

Harm 4: To avoid pressing on the mammary glands and causing mastitis and clogged milk ducts.

Regular bras with inflexible fabric and underwire may compress the mammary glands, causing mastitis and clogged milk ducts. Replace the regular bras, which are not only inconvenient when breastfeeding and embarrassing, but also can cause compression and pain with a new nursing bra.

Why do pregnant mothers choose to wear pregnancy/nursing bras?

  • Prevent saggy breasts
    During pregnancy, the breasts increase in size due to the stimulation of estrogen and progesterone, which is all preparing for breastfeeding. The muscles on both sides of the breasts may become relaxed due to the inability to support the growth of the breasts, resulting in sagging breasts. However, wearing a well-supportive nursing bra can prevent breast sagging. Professional maternity and nursing bras can help to lift and gather the breasts, avoiding compression of the breasts.
  • I do not feel any tightness
    With a growing baby bump, wearing a regular bra can cause discomfort and tightness. Therefore, during pregnancy, it is advisable for the mother to start wearing maternity & nursing bras. It is important to choose a nursing bra that is gentle on the skin and stretchy.
  • Avoid a decrease in breast milk supply
    Good nursing bras have large cup elasticity to prevent compression, thereby avoiding milk regression or clogged milk ducts. During pregnancy, breasts constantly enlarge, so wearing regular bras at this time could compress the mammary glands and reduce future milk production.
  • Lessen shoulder and back pressure
    Breastfeeding bras have widened shoulder straps, side wings, underbands, and back hooks to reduce the pressure of breast enlargement and minimize the pressure on the shoulders and back caused by bras. Many women can relate to this. Wearing regular bras for a long time can cause soreness and discomfort in the shoulders and back as the shoulder straps are too narrow. Therefore, for pregnant mothers who are prone to back pain, the design of breastfeeding bras is more thoughtful.

Many mothers neglect the protection of their breasts during pregnancy and childbirth. They either do not wear bras or choose loose-fitting ones. When breastfeeding, if they do not pay attention to breast care, it can easily lead to breast deformation and sagging, making it difficult to return to their previous shape.

Is it necessary to purchase nursing lingerie?

How to choose nursing bras? You should select nursing bras based on changes in your breasts and change your bra sizes. It’s not advisable to always wear the same size of nursing bra, as it is not beneficial for the breast. Right nursing bras should be both comfortably fitting and not make you feel too loose.


Tips for choosing a good maternity and nursing bra


  • The material is absorbent and breathable
    Due to hormonal changes, the body temperature of pregnant mothers will increase, making them more prone to sweating. Therefore, it is advisable for expectant women to choose breathable and sweat-wicking nursing bras that do not compress the breasts and cause discomfort. 
  • The bra is supportive
    The shoulder straps of nursing bras should be wide and adjustable to enhance tension and prevent sagging or deformation of the breasts. It is also advisable to choose nursing bras with front closure or adjustable strap clasps, not only for convenient wearing and removal, but also for ease of breastfeeding. Widening the side panels can help shape the breasts and prevent the axillary breast tissue. The design of detachable built-in breast pads allows mothers to easily place nursing pads to avoid milk leakage. When weaning and stopping breastfeeding, you can consider purchasing a soft underwire bra for shaping.
  • High elasticity does not constrict the breast
    Fabric with high elasticity ensures perfect coverage for a mother’s breasts during the period of engorgement and emptying after breastfeeding, helping to maintain breast shape. Throughout the entire pregnancy and breastfeeding period, it is important to choose nursing bras based on breast changes and to change sizes as needed. It is not advisable to continuously wear the same size nursing bra if it does not fit you anymore.
  • Antibacterial fabric
    During the lactation period, new mothers are prone to experiencing milk overflow. It is important to select nursing bras that have antibacterial and odor-resistant properties to ensure breast hygiene. Additionally, it is advisable to prepare several nursing bras throughout the pregnancy and nursing period for easier and frequent replacement.