August 31, 2026

Pregnancy week 12: symptoms, baby size and the end of the first trimester

Pregnancy week 12 is one of the most special moments of the whole journey, because it closes the first trimester. Your baby is now about 6 centimetres, roughly the size of a lime, and is starting to look a lot like a miniature newborn. It’s also the time when the risk of miscarriage drops noticeably and many women finally get a breather: the nausea eases and energy comes back. Let me tell you everything that’s happening.

If you’re coming from pregnancy week 11, this week is the doorstep to that reassuring change of stage. And to see the whole journey at a glance, check out our pregnancy week by week guide.

What is pregnancy week 12?

Pregnancy weeks are always counted from the first day of your last period (LMP), not from conception. So in week 12 you’re about 10 weeks from fertilisation, still in your third month (weeks 9–13) and in the final week of the first trimester.

This week matters for two reasons: first, your baby’s main organs are already formed and what’s left now is for them to grow and mature; and second, the risk of pregnancy loss drops significantly from here on, which is why many couples wait to announce the news until after this week.

Also, if your clinic has asked for it, this is still the window for the nuchal scan (done between weeks 11 and 13), so make the most of it if you haven’t had it yet.

What can you see on the week 12 scan?

The week 12 ultrasound tends to be one of the most exciting, because your baby already has a clearly human shape and won’t stop moving:

On screen you can see a well-proportioned little head, little arms and legs kicking, and a defined profile.
The crown-rump length (CRL) is measured — the most accurate way to date the pregnancy at these weeks and confirm your due date.
If you haven’t had it yet, the nuchal scan and the first-trimester blood screening can be completed.
And the most thrilling part for many mums: hearing the heartbeat, strong and fast (around 160–170 beats per minute). It’s a moment you never forget.

Here’s a fun detail: from this week the correct term starts to change. Many specialists consider that, from week 12, your little one can be called a fetus, since the embryo stage is over.

If you haven’t taken a pregnancy test yet, by week 12 your hCG levels are still very high and any test is very reliable. You can take our free online pregnancy test for guidance with your symptoms, and if you fancy a distraction, try our finger pregnancy test game: it’s just a game, not a real test.

What symptoms are normal in week 12?

For many women, week 12 is the light at the end of the first-trimester tunnel:

Nausea starts to ease: for many, morning sickness softens all of a sudden from now on. If yours are still strong, don’t worry: every pregnancy is different and some women carry them into the second trimester.
Energy returns: the exhausting tiredness of the start fades and, although you may still have ups and downs, in general you feel better.
Your breasts stay tender and bigger, though usually less sore than at the start. Your areolas may stay dark.
Fewer trips to the bathroom: your uterus is rising into the abdomen and pressing less on your bladder, so nighttime bathroom visits ease off.
A small bump may start to show low in your belly, especially if this is your second pregnancy or more.
Constipation and bloating: your digestion is still slower because of progesterone. Stay hydrated and eat fibre.
A little whitish vaginal discharge is common and normal; if it changes colour, smell or causes itching, mention it to your doctor.

Hardly any symptoms? Also completely normal: every pregnancy, every body and every week is unique. Enjoy the breather.

How big is the baby in week 12?

Week 12 baby, the size of a lime

The baby in week 12 measures about 6 centimetres (around 54–61 millimetres in total, head and body), roughly the size of a lime, and weighs around 14 grams. Still tiny, but this week it’s checked off a host of milestones:

The head is more and more proportional to the body, though it’s still large.
Fingerprints are now forming — a unique, personal feature.
It opens and closes its hands, curls its little fingers and can suck its thumb or finger.
Reflexes are starting to appear: if you touch its palm, it clenches it.
The intestines are now in place in the abdomen and starting small movements (the peristalsis that will move food after birth).
The kidneys make urine, which it releases into the amniotic fluid.
The first nail growth and the hair follicles from which hair will grow are appearing.
The vocal cords are beginning to form in the larynx.

Your uterus, meanwhile, has almost completely risen out of the pelvis and is starting to feel like a firm bump just above your pubic bone. It’s around now that many mums start to show.

Tips for week 12

Don’t skip the nuchal scan if your clinic has booked you in: it’s done between weeks 11 and 13, so this could be your last chance. Use it to clear up all your questions.
Keep taking folic acid: although the neural tube has closed, it’s still important this trimester. I explain everything in folic acid in pregnancy.
Make the most of the nausea easing to eat a balanced diet, but keep avoiding alcohol, smoking and raw foods.
Start thinking about maternity clothes: your uterus grows fast and, if your bump is showing, something flexible and comfortable will help.
Stay hydrated and move gently: walking, swimming or prenatal yoga help with constipation and your energy.
Don’t self-medicate: always ask your doctor before taking anything.
Work out your due date with the gestogram and track your week with how many weeks pregnant am I.

If you have intense one-sided pain, heavy bleeding or a fever, contact your doctor promptly.

FAQ

What month am I in during week 12?

You’re in your third month of pregnancy: weeks 9–13 make up month 3. Week 12 also brings you to the end of the first trimester.

How big is the baby in week 12?

About 6 centimetres (54–61 millimetres), the size of a lime, weighing around 14 grams. Its fingerprints are already formed and it opens and closes its little hands.

When does pregnancy nausea end?

For most women, the big improvement comes between weeks 12 and 14, as the hCG hormone starts to stabilise and the placenta takes over. Week 12 is often already the start of the relief.

When can I announce my pregnancy?

Many couples wait until after week 12 because the risk of loss drops significantly from here. But there’s no rule: you decide when it feels right.

Is my bump showing in week 12?

Your uterus already feels like a firm bump just above your pubic bone. On the outside, many women start to notice it, especially with their second pregnancy or more. Every body is different.

Does the fetus stage start in week 12?

Yes — many specialists consider that from week 12 the baby goes from being an embryo to a fetus, because the organs are formed and now only need to grow and mature.

Can I still be pregnant if I barely have symptoms?

Yes, absolutely. Not having nausea or discomfort doesn’t mean something is wrong: some women have almost no symptoms across the whole first trimester. If you’re worried, your doctor is the best person to reassure you.

Remember this article is for information only. If you have questions about your health or think something might be off, talk to your doctor. They can advise on the right tests and support you through this special time ❤️.