Changes to Your Breasts During Pregnancy: A Brief Week-by-Week Guide

Most people think of a growing stomach when they consider the bodily changes of pregnancy, but a woman’s breasts during pregnancy will also go through a series of changes throughout pregnancy.

Changes to the breasts occur because the body is preparing to produce milk in order to nourish a baby. The following guide will help women with understanding what the many changes during the entire course of their pregnancy and what to expect once their baby is born.

If you are a mom-to-be for the first time, you can also check our another article week by week pregnancy guide to know more!

breast changes during pregnancy week by week

First Trimester Changes to the Breasts

Weeks 1-2:

In the first weeks after implantation, there will not be much of a change in the breasts.

Week 3:

At this point, many women begin to notice that their breasts feel more sensitive, and they may feel tender when touched.

Week 4:

The nipples and sides of the breasts may begin to feel a little tingly along the area where the internal mammary artery runs.

Weeks 5-7:

Changes to hormones tell the breasts to grow more glandular tissue. They start to feel a little fuller or uncomfortable. The areolas around the nipple start to darken while the nipples become more prominent.

Weeks 8-10:

You may notice that blood vessels in the breasts are more noticeable. Due to increased volume, breasts may feel a little lumpier. A dark ring and small dots, called Montgomery’s tubercles, may spring up around the areola.

Weeks 11-12:

The breasts continue to feel tender, and the skin may feel very tight.

Second Trimester Changes to the Breasts

Weeks 13-15:

Breasts continue to grow in size, and areola pigmentation deepens. Uneven pigmentation may cause a slightly patchy appearance.

Week 16:

The breasts finally begin to feel less tender. At this point, colostrum, a type of thick, sticky, yellow fluid may begin to puss from the nipples when stimulated. In some cases, there may be a slight amount of blood too. 

Weeks 17-18:

Some women may develop lumps due to cysts, and it is a good idea to get these checked by your doctor.

Weeks 19-20:

The breasts response to estrogen and progesterone lessens, meaning they should begin to feel less tender and lumpy.

Weeks 21-24:

Your breasts start to undergo a new period of growth. This is the time when stretch marks may start developing along the bottom of the breasts.

Weeks 25-26:

The breasts may start to leak colostrum on their own without any stimulation or pressure. Depending on a woman’s original breast size, this new stage of growth may cause larger breasts to droop slightly. At this time you can also take breastfeeding preparation before your baby arrives.

Third Trimester Changes to the Breasts

Week 27:

At this point, the milk-producing glands in the breasts will be fully mature but most women will not begin lactating

Week 28:

The veins beneath the skin of the breasts will be very prominent and visible.

Week 29:

The nipples will become more prominent as progesterone production starts up again. Due to the dilated blood vessels throughout the breasts, they may develop rashes more easily, especially along the bra line.

Weeks 30-32:

Pimple-like bumps around the areola called Montgomery’s tubercles may begin to leak a type of creamy fluid that is meant to lubricate the nipples. The skin of the breasts will feel very dry and tight.

Week 32:

Even if you have not had colostrum leakage before, it will begin to appear as your milk comes in. It will gradually change from being thick and yellow to pale and thin. When this leakage happens, the nipples may feel slightly tingly or fizzy.

Weeks 33-36:

At this point, breast growth should be primarily done, though they may get slightly larger when filled with milk. This is a good time to go ahead and find nursing bras that will fit you after you give birth.

Weeks 37-38:

Your breasts might not look much different from the outside, but they will be going through changes on a cellular level that make them more resistant to breast cancer.

Weeks 39-40:

At this point, the uterus will become more sensitive to oxytocin, a hormone released when the nipples are stimulated. Since manipulating the nipples may stimulate contractions, it is only recommended to do so when you are ready to give birth.

What to Expect After Birth Baby

As your milk comes in, your breasts will begin to swell and they might feel a little lumpy or heavy. Breast size and feel will change slightly depending on whether you have breastfed recently or not.

Your breasts will continue to look larger and have darker nipples until you wean. Once you’ve stopped breastfeeding, allow up to 6 months for your breasts to readjust.

When your breasts return to their original size, there may be some permanent sagging or stretch marks due to the increase and decrease in size. Avoiding excessive weight gain, moisturizing the skin, and wearing supportive bras may help to reduce the effects.

Many women struggle with their postpartum body image and self-confidence. The natural changes that occur to your body should be loved and embraced, however, if you find yourself unable to embrace these changes it is important to consult a professional in order to restore your confidence and happiness.

Related Post:

What to Avoid During Pregnancy?

Week by Week Pregnancy Guide

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