From poems to art to magazines, breasts and breast size are often a hot topic of conversation. And one of these hot topics (and myths) is that a woman’s breast size increases after getting married.

While it seems unlikely the body knows the exact moment a person says “I do” as a means to increase breast size, this article will examine why this myth may have started in the first place.

Additionally, we’ll take a look at some factors that actually do increase breast size. Marriage isn’t one of them.

While no one knows exactly who started the rumor that marriage increases breast size, people have passed around this myth for centuries.

The most likely explanation for this is conceiving a child or traditional weight gain after marriage. Both of these things can happen whether a person is married or not.

Since marriage doesn’t increase breast size, here’s a list of some of the factors that actually do.


A woman’s breasts increase by both size and fullness while expecting. Reasons for this include hormonal changes that cause water retention and the amount of blood volume to increase, plus the body is preparing itself for breastfeeding.

Some people may find their cup size increases by one to two sizes. Their band size may increase as well due to rib changes to prepare for their growing baby.


Hormonal fluctuations related to menstruation can cause breast swelling and tenderness. Increases in estrogen cause the breast ducts to increase in size, usually peaking about 14 days in the menstrual cycle.

About 7 days later, progesterone levels reach their height. This also causes growth in the breast glands.


Breastfeeding can cause further increases to breast size. The breasts can vary in size throughout the day as they fill and empty with milk.

Some people find their breasts are actually smaller when they’re finished breastfeeding than their prepregnancy size. This isn’t always the case.


Taking certain medications may result in a modest increase in breast size. Examples include estrogen replacement therapy and birth control pills. Because birth control pills contain hormones, the growth effect may be similar to menstruation-related breast changes.

Some people may also find they retain more water when they start to take birth control pills. This can cause the breasts to appear or feel slightly larger.

As the body adjusts to the additional hormones associated with taking birth control pills, a person’s breast size may go back to their size before taking the pills.

Supplements are unproven

You may also see supplements that promise to help grow breasts. These usually contain compounds some consider precursors to estrogen.

However, there aren’t any studies to support that supplements can enhance breast growth. Like the idea that breasts get larger after marriage, breast growth supplements are likely a myth.

Weight gain

Because breasts are largely composed of fat, weight gain can also increase breast size.

According to an article in the journal Scientific Reports, a person’s body mass index (BMI) is the most significant predictor for breast size. The higher a person’s BMI, the larger their breasts are likely to be.

Some people tend to gain weight in their breasts first, while others gain weight in other locations. Unless you’re underweight, using weight gain as a means to enhance breast size isn’t the healthiest choice.

Abnormal growths

Breasts contain fatty and fibrous tissue. A person may develop fibrosis, or collections of fibrous tissue that may cause the breasts to appear larger in size. Usually, these growths aren’t troublesome.

A person can also develop cysts on their breasts. Cysts usually feel like round lumps that may be fluid-filled or solid. According to the American Cancer Society, women in their 40s are most likely to have breast cysts. However, they can occur at any age.

Most cysts and fibrous tissue aren’t harmful to a person’s health. However, if you have an area you’re worried about, talk to a doctor.

Saying “I do” doesn’t mean you’re also saying yes to breast growth.

Breast size has more to do with BMI, hormones, and your body’s genetic makeup. Heredity also has a lot to do with breast size. So, if you’re concerned one way or the other about marriage and breast size, you can put your fears to rest.