20 Weeks Pregnant: Halfway There, and Carrying Three Generations at Once

Last week, you may have felt your baby move for the very first time. This week, you reach the middle of it all. The halfway mark. And it comes with one of the most staggering facts in the whole of pregnancy, one that quietly links three generations of your family in a single moment. Let me show you.

Halfway there

Take a breath and let this land. You are halfway.

Twenty weeks ago, your baby was a single cell, smaller than this full stop. Today, that cell has become a kicking, hiccuping, hearing little person, with a heartbeat and fingerprints and a favourite way to lie. You grew all of that. And you have a just as remarkable stretch ahead of you, where your baby will grow from this midpoint into a full-term baby, ready for your arms.

It is worth pausing on. Halfway is a real milestone, and you have carried your baby every single step of the way to get here.

If you are carrying a daughter, you are carrying three generations

Of all the wonders in this pregnancy, this might be the one that takes my breath away the most.

If your baby is a girl, then this week, inside her tiny developing ovaries, she holds somewhere between six and seven million eggs. It is the most she will ever have. More than at her own birth, more than as a child, more than as a grown woman. Her entire egg supply peaks this week, right at the halfway point of your pregnancy, and from here it only ever declines. No new eggs are ever made again.

Now sit with what that means. Every one of those millions of eggs is a possibility, a potential child. So tucked inside your daughter, who is tucked inside you, are the very first beginnings of your grandchildren. Three generations of your family, folded one within the other, alive in your body in this single moment that will never come again.

And here is the part that joins it all up. This is exactly what once happened to you. When you were a tiny fetus, halfway through your own mother's pregnancy, the egg that would one day become your baby was already forming inside you. Your grandmother carried it without ever knowing. We reach back into one another so much further than we ever realise.

If you are carrying a son, or you do not yet know who is in there, this is still your story. It is precisely what unfolded inside you, twenty weeks into your own beginning. Either way, you are part of a chain that stretches back, mother within mother, longer than anyone can quite imagine.

Your baby's brain is mapping the world

There is a quieter milestone happening this week too, inside your baby's head.

The brain is beginning to set aside special territory for each of the senses. A region for smell. A region for taste. Areas for hearing, for sight, for touch. The map your baby will one day use to make sense of absolutely everything, your face, your voice, the smell of home, the taste of first foods, is being laid out, neighbourhood by neighbourhood, this week.

How big is my baby at 20 weeks?

Here is a fun quirk. From about now, your baby is measured head to heel, rather than head to bottom as before, because those little legs have finally uncurled and stretched right out. So the length suddenly seems to jump.

Head to heel, your baby is around twenty-five centimetres now, and weighs roughly three hundred grams. About the length of your forearm, hand to elbow, and growing stronger and rounder by the day.

What is happening in my body?

Your uterus has grown up to about the level of your belly button now, so your bump is unmistakable, and you are likely feeling your baby move more and more.

For many families, the detailed anatomy scan falls right around this week. So if yours is coming up, this may be when you get your wonderful, lingering look at your baby, and the chance to find out whether you are expecting a girl or a boy. You may notice your appetite is healthy and your energy fairly good. This is, for many women, the most comfortable stretch of the whole pregnancy. If that is true for you, enjoy every bit of it.

From Courtney. This is the fact that, of everything in this whole pregnancy, undoes me the most. If you are carrying a daughter, then this week her ovaries hold every egg she will ever have, six or seven million of them, more than at any other moment of her entire life. Which means that, right now, folded inside your body, are not only your daughter, but the very beginnings of your grandchildren. Three generations of your family, nested one inside the next, in a single moment that will never come again. And it happened to you too, once, inside your own mother, inside your grandmother. We carry each other so much further back than we ever realise. Halfway there, mama. Hold this one close.

The one thing to do this week

This week, take a moment to mark the halfway point, however small. You might snap a photo of your bump to look back on one day, jot down a few lines to your baby about how all of this feels right now, or simply sit quietly for a minute, hand on your belly, and let yourself feel how far the two of you have come. Twenty weeks ago, your baby was a single cell. Look at them now.

And then, as always, rest when you need to. Halfway is a good moment to be kind to yourself.

Coming up in week twenty-one

Next week, your baby sits down to its first proper meals. Your baby is swallowing more and more of the fluid around it, and that fluid carries the flavours of everything you eat, the garlic in your dinner, the sweetness of a pudding. Your baby is, astonishingly, beginning to taste the food on your plate.

Week twenty-one is where your baby develops a taste for life. 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

Baker, T. G. (1963). A quantitative and cytological study of germ cells in human ovaries. Proceedings of the Royal Society of London. Series B, Biological Sciences, 158(972), 417-433. https://doi.org/10.1098/rspb.1963.0055

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

Mayo Clinic. (2025). Fetal development: The second trimester. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20046151

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.