We’re friends, right? OK, good. So that means we can pretty much chat about anything, yes? Cool. Let’s talk about boobs--specifically, everything that happens to 'em throughout your life.

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in utero and infancy

Though you may not see those beauties for another 13 years, your breasts actually start to form during fetal development with a thickening of the chest area called the mammary ridge. By the time a baby girl is born, the early stages of a milk-duct system have formed.

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In your teens

They’re hereeeee! When you hit puberty, your ovaries start producing and secreting estrogen. Fat accumulates within the connective tissue, causing breasts to grow and 14-year-old boys everywhere to collectively lose their sh*t.

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In your 20s

Your breasts will probably be at their peak perkiness. Enjoy them now.

Don't freak out if you develop fibroadenomas, benign muscle tumors that can feel like marbles under your skin. They’re usually painless and vary in size, but you should consult a doctor to be sure you’re dealing with something benign.

 

boobs 30s
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In your 30s

You might get pregnant, which throws the girls for quite a few loops.

During pregnancy, your breasts may increase up to three sizes (the average woman gains two pounds just in her boobs) and your nipples may become more prominent. This happens because estrogen and progesterone are adding fatty tissue to your boobs and increasing blood flow to get ready to produce milk. (Which can actually happen before the baby is even born.)

You might also notice a darkening of your nipples and areolas, which--weird science fact--might be an evolutionary tool meant to make it easier for babies to find their food source when they can only distinguish light and dark.

Post-pregnancy, you could experience stretch marks as a result of the rapid growth (and rapid shrinkage) of your boobs. Pregnancy could also cause ptosis, or a drooping of the breasts. Sigh.

RELATED: 6 Boob Myths Debunked

boobs 40s
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In your 40s

You’ll probably get your first mammogram, which can often help detect breast cancer in its early stages, when treatment is most likely to be successful.

You might notice your breasts getting subtly softer as your ovaries start to produce less estrogen.

boobs 50s
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In your 50s

At this age your boobs typically go through a process called involution, during which breast tissue is replaced by fat, which is softer, and makes them feel less firm. (But fear not: That’s why God invented shapewear.)

RELATED: 9 Tricks for a Better Fitting Bra

boobs 60s
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In your 60s, 70s and beyond

Following menopause, your breasts effectively go into retirement. Your ovaries stop producing estrogen, so soft, fatty tissue becomes the main tissue of the breast. But that doesn’t mean you have to put the girls to rest. Black demi cup with plunging white blazer? Go for it!

RELATED: 19 Things Only Women with Big Boobs Understand

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