Breast changes during or after pregnancy

Breasts change during pregnancy to prepare them for feeding a baby.

These changes are caused by an increase in hormones, and may include:

• Tenderness or a change in sensation of the nipple and breast
• An increase in breast size
• Changes in the colour and size of the nipples and areola
• Bigger and more noticeable Montgomery glands (small, raised bumps on the areola that produce fluid to moisturise the nipple)

Breasts can produce milk from about the 16th week of pregnancy. It’s not unusual for small amounts of straw-coloured fluid called colostrum to leak from the nipples. If you’re worried this 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.

If your breasts are painful, you can talk to your GP or midwife for advice on pain medication.

The breasts and nipples

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

The coloured area of skin around the nipple is called the areola. There are some small, raised bumps on the areola called Montgomery glands. These produce fluid to moisturise the nipple.

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.

The National Childbirth Trust (NCT) has further information on maternity and nursing bras.

Breast lumps that are benign (not cancer) 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)

If you had a fibroadenoma before you were pregnant, you may find this gets bigger during pregnancy.

Some women occasionally experience blood leaking 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 this checked by your GP.

Around 3 days after giving birth, colostrum becomes diluted by additional fluid. This 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. This is known as the “let down” reflex (when hormones tell your breasts to produce milk).

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. Putting disposable or washable breast pads in your bra can help you feel more comfortable and prepared.

Around 2 to 4 days after giving birth, your body begins to produce breast milk. This is known as your milk “coming in”. Sometimes this can make it more difficult to breastfeed.

It’s important to get support from your midwife, health visitor or breastfeeding counsellor as soon as possible if you have any of the problems below in one or both breasts. You can continue to breastfeed but you may need additional support.

Sore and cracked nipples

Nipples can become sore and cracked if the baby does not attach to the breast correctly. This can happen if the baby only sucks the nipple rather than the whole areola being in their mouth, as the baby’s tongue or roof of their mouth rubs on the nipple.

Your nipples won’t heal if your baby does not attach to the breast properly.

It’s important to get support from a midwife, health visitor or breastfeeding counsellor as soon as possible if feeding is painful.

Engorgement

Breast engorgement is when the breasts become overfull with milk.

Breast engorgement generally happens when milk first comes into the breasts. It can also happen as your baby gets older and starts eating solids, as you may breastfeed less frequently.

Some women describe their breasts as feeling hard, warm and throbbing.

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

You may be able to relieve breast engorgement 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:

• Wearing a well-fitting nursing bra that’s supportive but does not restrict your breasts
• If your breasts are leaking, applying warm flannels just before expressing
• Applying a cold pack or damp flannel to your breasts after feeding or expressing milk (this may help to reduce pain and swelling)
• Taking 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 you’re breastfeeding. This can also happen when you stop breastfeeding.

You may have a small, painful, hard lump or a bruised feeling.

Things that may help relieve a blocked duct 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 or having a warm shower to encourage milk flow
• Drinking lots of water to stay hydrated
• Ensuring your bra and clothes are not too tight so the milk can flow freely

If you think you have a blocked milk duct, get it checked by your midwife, health visitor, GP or breastfeeding counsellor, especially if you have fever or flu-like symptoms.

Mastitis

If breast engorgement or blocked milk ducts continue, the breast may become inflamed or infected. This is called mastitis. It can affect one or both breasts.

Symptoms of mastitis may include:

• Your breast or breasts being red, hot and painful
• Flu-like symptoms, such as headaches, nausea and a raised temperature

Your baby may be unsettled feeding on the affected breast or breasts. This is because the milk is flowing slower.  

It’s important to continue breastfeeding or expressing, especially from the affected breast. This may help to clear the infection and is not harmful to your baby.

You do not need to increase the number of times you normally breastfeed or express. There’s no evidence this clears the blockage any quicker but it may increase the inflammation.

Other things that may help relieve symptoms of mastitis include:

• Applying cold to the affected area
• Staying hydrated
• Using paracetamol or ibuprofen to help with pain or fever
• Avoiding tight or restrictive clothes or bras until your symptoms improve

If you think you have mastitis, you’ll need to see your midwife, health visitor or GP. They may prescribe you antibiotics or anti-inflammatory drugs.

Breast abscess

You may develop a collection of pus (abscess) in the breast if mastitis or an infection is not treated.

It’s very important to see your GP if you think you have a breast abscess, as they may need to refer you to a breast clinic.

A breast abscess is usually treated with antibiotics and is also often drained using a needle and syringe. Sometimes this is done using an ultrasound scan to guide the needle into the correct place.

If the abscess is large, a small cut to the breast allows the pus to drain away. You will usually have an injection of local anaesthetic to numb the area first.

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

Thrush

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

Your nipple may become:

• Itchy
• Painful
• Sensitive to touch

Some women have shooting pains deep in the breast that start after feeding and can last for a few hours.

Thrush can be difficult to diagnose because many of the symptoms are similar to those caused by the baby not being latched onto 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
• 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)

If you think you or your baby have these symptoms, talk to your GP, health visitor or midwife. Your GP may prescribe antifungal creams or tablets to treat the thrush infection. Both you and your baby will need to have treatment at the same time.

If you choose not to breastfeed

If you choose not to breastfeed and you’re not expressing milk, you’ll stop producing milk.

Your breasts may feel heavy, uncomfortable and sore for a few days.

Wearing a supportive bra and taking pain relief may help.

If you want to stop breastfeeding

You will continue to produce milk as long as you’re breastfeeding.

When you want to stop breastfeeding it’s best to do it gradually by reducing the length and number of breastfeeds. This should prevent your breasts from becoming engorged.

Your body produces milk on a supply-and-demand basis, so this will naturally reduce the amount of milk you produce. You may like to start by dropping 1 feed a day.

Milk may leak from your nipples for several weeks after you stop breastfeeding, especially if something triggers the “let down” reflex. You may have:

• A tingling feeling in your breasts and nipples that can be quite strong
• A feeling of sudden fullness

Your breasts will slowly reduce in size as you stop breastfeeding.

Your breasts probably won’t look or feel the same as they did before pregnancy, whether you’ve breastfed or not.

You may have gained or lost weight, and it’s not unusual for your breasts to have changed in size and shape compared to before pregnancy.

These are normal changes your breasts go through at different stages in life.

It’s important you get to know how your breasts look and feel after pregnancy so you can be aware of any new changes. Find out more information about checking your breasts below.

Changes to your breasts during and after pregnancy can make you feel anxious.

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

Useful links

NHS UK – offers guidance on breastfeeding

The Breastfeeding Network – offers independent breastfeeding support and information

National Breastfeeding Helpline – offers independent breastfeeding support and information