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Breast changes during or after pregnancy

Read more about breast changes during and after pregnancy, including how to be breast aware.

1. Being breast aware in pregnancy

It’s important to be breast aware during and after pregnancy. This means getting to know how your breasts look and feel so you know what’s normal for you. This will help you feel more confident about noticing any unusual changes.

Breasts change a lot during pregnancy, so it can be difficult to notice any unusual changes at this time. If you’re unsure about any change to your breasts, talk to your midwife or GP.

The breasts and nipples

Side-on illustration of the breast, with arrows to the chest, lobules, nipple, ducts, fatty tissue and ribs
A side-on diagram of the breast.
A side-on diagram of the breast.
An illustration of a breast nipple. One arrow points to the areola around the nipple, and another arrow points directly to the nipple itself. In this drawing, the breast is light brown and the nipple is a darker brown.
The nipple.
The nipple.

Breasts are made up of lobules (milk-producing glands) and ducts (tubes that carry milk to the nipple). These are surrounded by glandular, fibrous and fatty tissue. This tissue gives breasts their size and shape.

On the there are some small raised bumps called Montgomery glands, which produce fluid to moisturise the nipple.

2. How do breasts change during pregnancy?

Your breasts change during pregnancy to prepare them for feeding your baby. These changes are caused by an increase in hormones, and may include the following:

  • Tenderness or a change in sensation of the nipple and breast
  • An increase in breast size
  • Changes in the colour and size of nipples and areola
  • Bigger and more noticeable Montgomery glands

From about the 16th week of pregnancy the breasts are able to produce milk. It’s not unusual for small amounts of straw-coloured fluid called colostrum to leak from the nipples. If you’re worried that it may be noticeable on your clothes, you can use a breast pad (a disposable or washable fabric pad) inside your bra.

In the last few weeks of pregnancy the nipples become larger and the breasts continue to grow as the milk-producing cells get bigger. Your breasts may feel uncomfortable and sometimes painful. Wearing a well-fitting bra may help relieve any pain or discomfort. It’s fine to sleep in a bra if it’s more comfortable for you.

Women are usually advised to avoid certain types of pain relief while pregnant, but if your breasts are particularly painful you can talk to your GP or midwife for advice on pain medication.

3. Are breast lumps common during pregnancy?

Breast lumps sometimes develop during pregnancy. The most common ones are:

  • Cysts (fluid-filled sacs)
  • Galactoceles (milk-filled cysts)
  • Fibroadenomas (which develop in the lobules of the breast)

These are benign (not cancer) breast conditions. If you had a fibroadenoma before you were pregnant you may find this gets bigger during pregnancy.

Breast cancer in women of child-bearing age and during pregnancy is uncommon. However, you should get any new breast lump, or any changes to an existing breast lump, checked by your GP.

4. Is it normal to have blood from your nipple?

A few women may have occasional leakage of blood from the nipple. This is due to an increase in the number and size of blood vessels. Although this can be normal during pregnancy, it’s best to get any leakage of blood from the nipple checked by your GP.

5. Finding the right size bra during pregnancy

As your breasts increase in size you should check that your bra isn’t too tight. It’s worth visiting a department store or lingerie shop to be measured and have your bra size checked by a trained bra fitter. Or you could contact the National Childbirth Trust (NCT).

A bra fits well if:

  1. Your breasts fill the cup of the bra leaving no loose fabric and it contains the whole breast without any bulging at the top, bottom or sides
  2. The strap at the back doesn’t dig in
  3. The shoulder straps do not carry the full weight of your breasts, stay in place when you lift your arms above your head and fit closely to your body without digging in
  4. The strap round the back and the front underband lie close to your body and are at the same level at the front and back
  5. With an underwired bra, the underwire lies flat against your body and supports the underneath and sides of your breast without digging in or gaping
  6. The bra fits on the loosest set of hooks so that when it begins to stretch with time you can tighten it

You may find it more comfortable to wear a maternity or soft-cup bra. These types of bras can also be worn in bed if you feel you need extra support while sleeping.

If you’re hoping to breastfeed, you may want to buy a couple of nursing bras. These have cups that unfasten and make it easier to feed your baby. The best time to be fitted for a nursing bra is a few weeks before your baby is due when your breasts will have done the majority of their growing.

6. How do breasts change after birth?

Following the birth of a baby, oestrogen and progesterone levels decrease quickly. Around the third day or so after the birth the colostrum becomes diluted by additional fluid that makes it look much whiter. Around this time your breasts may start to leak milk.

When a baby sucks at the breast it triggers nerves that carry messages to the brain that milk is needed. Some women find milk leaks from the nipple when they hear their baby cry, or if their breasts are full and they feel emotional.

This can happen quite a lot in the first few days after you give birth and can sometimes be embarrassing. Putting disposable or washable breast pads in your bra can help you feel more comfortable and prepared.

Changes due to breastfeeding

The changes that happen to the breasts during pregnancy prepare them for feeding a baby. The Department of Health recommends exclusively breastfeeding for the first 6 months of your baby’s life, if possible, and then continuing to breastfeed alongside solid foods for as long as mother and baby wish. Research shows that breastfeeding may reduce the risk of developing breast cancer.

Although breastfeeding is a natural process it can sometimes take a little time to get right. If you’re finding it difficult, talk to your midwife or health visitor.

Some women choose not to breastfeed because it hasn’t been possible or they simply do not feel it is the right choice for them and their baby. There is not a right or wrong decision; you just need to feel you’ve made the best decision for you and your baby.

Women who’ve had breast surgery – due to breast cancer, breast reduction, surgery to the nipple or breast implants, for example – may find that they’re unable to breastfeed. This is due to the formation of scar tissue. However, some women are still able to breastfeed after surgery. You can ask your midwife, health visitor or breastfeeding counsellor for help if needed.

You can find more information about breastfeeding on the NHS website. You can also call the National Breastfeeding Helpline on 0300 100 0212 for confidential breastfeeding support and information. 

7. Possible breast problems after pregnancy

The following describes some of the problems you may experience when your milk ‘comes in’ (when your body begins to produce breast milk and no longer colostrum). Some of this information may apply whether you decide to breastfeed or not.

Sore and cracked nipples

Sore and cracked nipples can develop if the baby does not attach to the breast correctly. If the baby only sucks the nipple, rather than the whole areola being in their mouth, the baby’s tongue or roof of the mouth rubs on the nipple. The nipples can quickly become sore and sometimes cracked.

The nipples won’t heal if the baby does not attach to the breast properly, so if feeding is painful it’s important to get support from a midwife or breastfeeding counsellor as soon as possible.


Breast engorgement is when the breast becomes overfull of milk. Some women describe their breasts as feeling hard, warm and throbbing. Breast engorgement generally happens when milk first comes into the breasts.

If your breasts are engorged and you’re continuing to breastfeed, it’s important to make sure your baby is attaching to the breast correctly. Your midwife, health visitor or breastfeeding counsellor can help you with this.

Breast engorgement may be eased by:

  • Feeding your baby on demand
  • Expressing (squeezing out) or using a breast pump to release a small amount of milk so it’s easier for your baby to attach to your breast

You may also find the following helpful:

  • Wear a well-fitting nursing bra that does not restrict your breasts
  • If your breasts are leaking, apply warm flannels just before expressing
  • Apply chilled cabbage leaves to your breasts after feeding or expressing milk – this may help to reduce pain and swelling
  • Take paracetamol at the recommended dose to ease the pain – this is safe to take while you’re breastfeeding

Blocked milk ducts

Sometimes a milk duct becomes blocked while breastfeeding. This can also happen when you stop breastfeeding. You may experience a small, painful, hard lump or a bruised feeling.

Things that may help include:

  • Feeding your baby more often
  • Changing position when you’re feeding (this may help to drain the area more fully)
  • Gently massaging the lump towards the nipple while your baby is feeding
  • Applying warm flannels to the breast
  • Ensuring your bra and clothes aren’t too tight so the milk can flow freely


If breast engorgement or blocked milk ducts continue the breast may become inflamed or infected. This is called mastitis. The breast may be red, hot and painful. Mastitis can cause flu-like symptoms including headaches, nausea and a raised temperature.

It’s important to continue to breastfeed frequently, especially from the affected breast, as this helps to clear the infection and isn’t harmful to the baby.

If you think you might have mastitis you’ll need to see your doctor as it may need treating with antibiotics or anti-inflammatory drugs.

Breast abscess

If mastitis or an infection isn’t treated, some women go on to develop an abscess (a collection of pus) in the breast. Breast abscesses are not common – if you think you have an abscess it’s very important to see your GP. They may refer you to a breast clinic.

Abscesses are usually treated with antibiotics and are often drained using a needle and syringe. An ultrasound scan may be used to guide the needle into the correct place. If the abscess is large, a small cut is made in it to allow the pus to drain away. An injection of local anaesthetic is usually given to numb the area first.

As with mastitis, your doctor will usually advise you to continue breastfeeding or use a breast pump to express the milk regularly.


Thrush (candida albicans) is a yeast infection that may occur on the nipple and areola during breastfeeding. It can develop following cracking or damage to the nipple but may also happen suddenly, even when you’ve been breastfeeding for some time.

The nipple may become itchy, painful and sensitive to touch. Some women find they have shooting pains deep in the breast that start after feeding and can last for a few hours.

Thrush can be difficult to diagnose as many of the symptoms are similar to those caused by the baby not being latched on to the breast properly during breastfeeding.

Thrush can also be passed from mother to baby. Signs of thrush in your baby may include a creamy patch on the tongue or in the mouth which does not rub off. Babies may also get a sore mouth which can cause restlessness during feeding and pulling away from the breast. Nappy rash (red rash or soreness that’s slow to heal) is another symptom of thrush.

If you think you have these symptoms, talk to your GP or health visitor. Both you and your baby will need to have treatment at the same time.

8. What happens if I do not breastfeed, or want to stop?

If you choose not to breastfeed and no milk is being expressed you’ll stop producing milk. You may find your breasts feel heavy, uncomfortable and sore for a few days. Wearing a supportive bra and taking pain relief may help.

Women continue to produce milk as long as breastfeeding continues. When you stop breastfeeding it may take some time for the milk production to stop completely.

If you stop breastfeeding too quickly it can lead to engorgement. When you want to stop breastfeeding it’s best to gradually reduce the length and number of your breastfeeds. You may like to start by dropping 1 feed a day. Your body produces milk on a supply-and-demand basis so this will naturally reduce the amount of milk you produce.

Milk may leak for several weeks after you stop breastfeeding if something triggers the ‘let down’ reflex (when hormones tell your breasts to produce milk). You may experience a tingling feeling in your breasts and nipples that can be quite strong, a feeling of sudden fullness, or you may notice that milk starts to leak from either or both breasts.

When you stop breastfeeding your breasts will slowly reduce in size.

9. Your breasts after pregnancy

After pregnancy, whether you have breastfed or not, your breasts probably won’t look or feel the same as they used to. You may have gained or lost weight, and it’s not unusual to find your breasts have altered in size and shape compared with before pregnancy.

These changes are part of the normal changes your breasts go through at different stages in life. It’s important that you get to know how your breasts look and feel now so you can be aware of any new changes. Find out more information about checking your breasts below. 

10. Further support

Changes to your breasts during and after pregnancy can make you feel anxious or you aren’t in control.

If you’re finding it difficult to cope, talk to your GP, or you can call our free helpline below and talk to one of our experts.

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Quality Assurance

Last reviewed in October 2019. The next planned review begins in February 2023.

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