"Breasts are the most changing part of the female body, especially during pregnancy." — Nina Cingel, lactation consultant at De Boezemvriend
She's right. And yet it's a topic most women only encounter once it's already happening. What exactly happens to your breasts during pregnancy? When do they change? And what can you expect during the postpartum period and beyond?
Nina Cingel guides mothers through breastfeeding questions daily at her practice De Boezemvriend in Amsterdam. She explains it — trimester by trimester.
First trimester: the fastest changes
Most women notice changes in their breasts before they've even taken a pregnancy test. Sore, sensitive or itchy breasts are often one of the first signs.
What's happening: under the influence of the pregnancy hormones oestrogen and progesterone, your milk glands begin to swell. Your breasts are preparing for milk production — a process that's actually set in motion before a girl is even born.
"In the first three months you see the most changes," Nina explains. "Your breasts grow quickly in volume and you notice your bra no longer fits properly."
What you'll notice:
- Breasts become larger and fuller — primarily in cup size
- Sensitive, sore or itchy nipples
- Swollen milk glands
- Nipple area may become lighter or darker
The good news: for most women, these discomforts ease after the first trimester.
Second trimester: a relative period of calm
After the rapid growth of the first trimester, things tend to settle. Your breasts have grown but are changing less quickly. Many women find this the most comfortable trimester of the three.
What's happening underneath: halfway through pregnancy, your breasts begin producing milk. Pregnancy hormones are holding back full milk production for now — but your body is preparing.
What you may notice:
- Your areola becomes darker
- Nipples may become firmer or more prominent
- Occasional moisture or light discharge — this is colostrum, your body's first milk
- Montgomery glands (small bumps on the areola) become more visible
Those Montgomery glands are fascinating: they secrete a fluid that keeps your nipples supple and produces a scent that helps your baby find your nipples after birth.
And then there's the ribcage. From the end of the second trimester, your chest circumference starts to increase — not just your breasts themselves, but the space around them. Your ribcage expands to make room for your growing baby. On average, your chest circumference grows by 7 to 10 centimetres. That's two to three band sizes.
This is the point at which many women find their bra stops fitting — and when the search for a good maternity bra really begins.
Third trimester: preparing for birth
Towards the end of pregnancy, your breasts begin to change again. Your body is getting ready for birth and milk production.
"At the end of your pregnancy, breast development picks up again," Nina explains. "You'll notice swollen milk glands and possibly that your bras no longer fit — this is all completely normal."
What you'll notice:
- Breasts become even heavier and fuller
- Ribcage is at its widest — band size is at its largest
- Nipples may begin producing colostrum
- Skin may feel tight or itchy from the growth
This is also when many women start looking at nursing bras for the first time. Nina's advice: do that in the third trimester, not right after birth. "After delivery, your breasts swell significantly due to engorgement. That's a temporary phase lasting up to 72 hours — not a good moment to be buying new bras."
Postpartum: the big change
After birth, the moment of truth arrives. Your breasts swell as your milk comes in — sometimes significantly.
"After your baby is born, you often end up with even larger breasts that feel like they might burst with milk," Nina explains. "This is a temporary phase that lasts up to 72 hours."
After that, milk production stabilises if you're breastfeeding. Your breasts gradually reduce in size. After around 8 weeks it can feel like there's not much left — but that's because they're settling and adjusting to your baby's demand.
What you need postpartum:
- A bra that's comfortable to sleep in
- Soft, breathable fabric against sensitive skin
- Easy access for feeding — without fiddly clips or complicated construction
- Support that adapts as your size keeps changing
After pregnancy: when will you fit into your old lingerie again?
"It's possible that after breastfeeding you'll have completely different breasts, or that your pregnancy breasts return to their original shape," Nina says. "It depends on many factors. Everything is normal."
Some women return to their pre-pregnancy size. Others find a new cup size — larger or smaller. Shape can change. And that's okay.
Nina's most important advice: "It's completely normal for your breasts to change during this period. Give yourself time."
What this means for your bra choice
Your breasts change differently in each trimester — and that calls for a bra that moves with them.
In the first trimester, you grow mainly in the cup. Going up one cup size still works for now.
From the second trimester, your ribcage starts to grow too. An extender might seem like the solution — but it doesn't fix the problem. The moment you extend the band, the whole bra shifts forward and the cups no longer sit properly. The result: pinching in the cup and digging into your back. At the same time.
What you actually need is a bra that grows with you in both cup and band — from the first trimester to the last feed. Without extenders, without interim purchases.
The Feelou bra is the only model with a patented growing system that accommodates both. It grows 2 to 3 cup sizes and at least 10 cm in circumference. Made from TENCEL™ Modal — softer than organic cotton, antibacterial and gentle on sensitive skin.
Article written in collaboration with Nina Cingel, lactation consultant at BVC Amsterdam
