Breast Changes During Pregnancy

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Breast changes during pregnancy

You'll notice some changes in your breasts as your body gets ready to breastfeed.

First trimester

Your pregnancy hormones cause normal breast tissue to change into milk-producing tissue. This change happens as early as the first trimester (weeks 1 to 12).

Early on in the pregnancy, you may notice a tingling sensation in your breasts. They may feel tender and sore. This is due to increasing levels of the hormone progesterone.

You may also notice small bumps on your areola (the area around the nipples). This is called Montgomery's tubercles. They are sweat glands that produce an oily substance to moisturise the areola.

Second trimester

Your nipples and areola may darken in colour as your pregnancy progresses.

The veins on the surface of your breasts may become more noticeable. You may also notice stretch marks on your breasts.

From about week 16, your breasts are ready to produce milk. This first milk is called colostrum and is yellow. It is often called 'liquid gold'.

Your first breast milk or colostrum

Third trimester

Your breasts may leak colostrum and you may be able to express small amounts by the end of week 36. Only do this if advised to by your midwife or GP.

Learning to hand express and store colostrum can help you improve your breast milk supply. It can make breastfeeding easier after your baby's birth.

In the last few weeks of pregnancy, your nipples and your breasts become larger.

When to see your GP

Non-urgent advice: Contact your GP if

you notice any of the following changes during pregnancy:

• a lump on your breast
• changes in an existing lump on your breast
• bleeding from your nipples

Normally these changes are nothing to worry about. But they need to be checked in case of an underlying condition.

How to check your breasts

Breast lumps

You can sometimes get breast lumps during pregnancy. Most of the time, these are benign and caused by hormonal changes.

Breast cancer is not common in younger women or during pregnancy. But it's important to get breast lumps checked by your GP before and after birth.

If you have an existing lump that changes during pregnancy, get this checked too.

Breast lumps

Blood from nipples

Sometimes blood-stained fluid may leak from your nipples. This can be normal, but it's important to see your GP or breastfeeding specialist if you notice it.

This is commonly known as 'rusty pipe syndrome'. It usually disappears after a few feeds.

It is normally caused by:

• increased blood flow
• quick development of milk producing glands
• damage (trauma) to the breast or nipples

Preparing for breastfeeding

During pregnancy, your breasts get ready for breastfeeding by making milk for your baby. Becoming familiar with and handling your breasts during pregnancy is an important part of preparing to breastfeed your newborn.

Preparing for breastfeeding while pregnant

Connect with your local breastfeeding group

It is helpful to join a breastfeeding support group during pregnancy. You can meet other new mothers and hear about their experiences.

Find a breastfeeding support group near you

Pregnancy bras

If you choose to wear a bra during pregnancy, make sure it is is well-fitting and not too tight. It is important to feel comfortable.

To find a well-fitting bra, make sure:

• it is not too tight or loose
• it is not wired or padded
• the strap at the back does not cut into your skin
• your breasts fill the fabric of the cup with no loose fabric - there should also be no bulging over the top, at the sides or underneath
• the shoulder straps stay in place without digging into your skin
• the strap around the back and the front underband are roughly at the same level

You can find good quality pregnancy and nursing bras in many shops. Ask the shop assistant to help you find the right fit. You can also buy maternity bras online.

If you do not normally wear a bra, there is no need to wear one during breastfeeding.

More in Stages of pregnancy

First trimester

• What to expect in the first trimester
• Due date calculator
• 0 to 8 weeks pregnant
• 9 to 12 weeks pregnant

Second trimester

• What to expect in the second trimester
• 13 to 16 weeks pregnant
• 17 to 20 weeks pregnant
• 21 to 24 weeks pregnant
• 25 to 28 weeks pregnant

Third trimester

• What to expect in the third trimester
• 29 to 32 weeks pregnant
• 33 to 36 weeks pregnant
• 37 to 40 weeks pregnant

Body changes

• Breast changes during pregnancy

Page last reviewed: 15 October 2025 Next review due: 15 November 2028