11 Weeks Pregnant: Practising to Breathe, Months Before the First Breath

Last week, your baby grew ten tiny fingers and a fingerprint all their own. This week, that little body comes alive, and begins to rehearse something it will not truly need for another six months. A breath.

Welcome to week eleven, the home straight of the first trimester. Your baby is wriggling, stretching, opening and closing both fists, and quietly practising to breathe in a place where there is not a single molecule of air. Let me show you.

Your baby is practising to breathe

This is one of those facts that I find genuinely astonishing.

Around now, your baby's tiny chest begins to move. The little diaphragm, the muscle that will power every breath of their whole life, starts to pull in and push out, drawing the surrounding fluid gently into the lungs and back out again.

There is no air in there. There is nothing to breathe yet, and there will not be for months. And still, your baby practises, over and over, training those brand new muscles in the dark, getting ready for a moment that is half a pregnancy away. The first real breath. The one that comes in the bright noise of the birth room, that fills the lungs for the very first time and turns into a cry, the sound you will know in an instant as your own. Your baby is, this week, beginning to rehearse for it.

A tiny explorer

Your baby is also, finally, on the move.

Those hands that only just finished forming are opening and closing into little fists. The mouth opens and closes. The knees and elbows and wrists and ankles are all working now, and your baby is twisting, stretching, and somersaulting through its weightless world with a freedom it will never quite have again.

And here is the bittersweet part, the same one I keep coming back to. All of this rolling and tumbling is happening inside you, today, and you cannot feel a single thing. There is still too much room and too little weight. The first flutters you will actually feel are many weeks away yet, somewhere in the second trimester. For now, your baby dances on, in secret, just for itself.

A skeleton turning to bone

Something quieter is happening deep inside too.

Until now, your baby's frame has been laid down in soft, rubbery cartilage, more like the tip of your nose than anything hard. This week, that begins to change. Real bone starts to form, hardening first in the skull and in the long bones of those busy little arms and legs. The scaffolding your baby was built on is slowly, steadily, setting into a true skeleton.

How big is my baby at 11 weeks?

This is a big growth week. Your baby is now around five centimetres long, head to bottom, and still under ten grams, so light you would barely feel the weight of them in your palm.

The head is still about half of that, the brain forever racing ahead, but the body is finally beginning to catch up. Between roughly week nine and week twelve, your baby very nearly doubles in length. Growing, as babies do, faster than seems quite possible.

Will people be able to tell yet?

Probably not, not quite yet.

Your uterus is growing, roughly the size of a grapefruit now, but it is still tucked low behind your pelvic bone, so most women are not visibly showing at eleven weeks, especially with a first baby. You might notice your waistband getting snug, or a new bloated, full feeling, which is partly your pregnancy hormones quietly slowing your digestion so your body can draw every last nutrient from your food.

As for the nausea, some women find it begins to loosen its grip right about now. Others still have a week or two to go. Both are completely normal, so please hold on if you are not there yet.

From Courtney. Week eleven has a particular feeling to it, I think. You are so close to that first big scan now, so close to the end of this hard, hidden first trimester, that you almost do not want to breathe too loudly in case you jinx it. I remember holding my excitement carefully, like something I was not quite allowed to have yet. If that is you, I understand it completely. But let me gently say this. Your baby is in there right now, rolling and stretching and practising its very first breaths, growing faster this week than at almost any other time. It is real. You are allowed to let yourself feel it. Nearly at the trimester line, mama. So very nearly there.

The one thing to do this week

Keep your folate going, or start it now if you are only just beginning. No guilt, ever.

If your first big scan is coming up in the next week or two, the one many women have around twelve to thirteen weeks, this is a lovely time to think about who you might want there with you, and whether you would like to take a photo home. And if you have been quietly wondering when and how to share your news, there is no right answer. Some tell the world the moment they see that scan, others hold it close for longer. Whenever feels right to you is exactly right.

Coming up in week twelve

Next week is a milestone, the one so many women count down to. The end of the first trimester.

Your baby's major organs are all formed and quietly working now, the risk of miscarriage drops considerably, and for many women the nausea at last begins to ease. It is also when a great many mothers have their first proper scan and see, for the very first time, their baby wriggling and waving on the screen. Week twelve is a big one. I will see you there.

Written by Courtney Garland, NICU nurse, lactation consultant and mother of four, and founder of The Mama Years. This is here to inform and reassure you. It is not a substitute for medical advice, so always follow the guidance of your own doctor or midwife.

The Mama Years. 2026.

References

Cleveland Clinic. (2023). Fetal development: Stages of growth. https://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth

March of Dimes. (2023). Pregnancy week by week. https://www.marchofdimes.org/pregnancy-week-week

Mayo Clinic. (2025). Fetal development: The first trimester. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302

Merck Manual. (2024). Stages of fetal development (Consumer Version). https://www.merckmanuals.com/home/women-s-health-issues/normal-pregnancy/stages-of-fetal-development

The Mama Years is written by Courtney Garland, a NICU registered nurse and IBCLC lactation consultant, against the research. When the science is genuinely unsettled, she says so instead of guessing. Nothing here replaces the advice of the clinician looking after you.