12 Weeks Pregnant: Symptoms, Ultrasound and Baby Bump


What to expect at 12 weeks pregnant. Everything you need to know about your changing body and growing baby as you reach the end of your first trimester.

Congratulations, you’ve survived your first trimester. For many women, twelve weeks pregnant is usually the time when you start to share your pregnancy news with extended family and friends. A lot of expectant mothers choose to wait until after the 12-week scan, as this is when you are considered to be out of the miscarriage ‘danger zone’.

At this stage, you might start to notice some of the early signs and symptoms of pregnancy wearing off. Many mums-to-be claim they really start to enjoy their pregnancies as they approach the second trimester. However, there are still a lot of changes going on in your body at 12 weeks pregnant.

Read on to find out more about what’s happening with your baby and body in week 12.

Think you missed something? Re-visit what to expect at 11 weeks pregnant or head over to our pregnancy week by week guide for more information at every stage of your pregnancy.

Your Baby at 12 Weeks Pregnant

As you approach the last week or so of your first trimester, your baby will be about the size of a lime. At 12 weeks, the foetus is just over two inches long and has doubled in size over the last three weeks.

baby-size-lime-12-weeksIn terms of development, your baby will be reaching a lot of milestones by the three-month mark. Now that their tiny little fingers and toes have formed, at 12 weeks your baby will be able to curl them. In fact, your little one is now moving around quite a bit. The eye muscles are able to clench and your baby can make a sucking motion.

Moreover, if you press into your tummy, you’re baby will react. It’s unlikely you’ll be able to feel it, but the foetus has developed a startle reflex (known as the Moro reflex). This also means your baby can hear and react to sounds by opening and closing its arms and legs.

Your baby is also busy making white blood cells in its bone marrow to build up the immune system and help fight off all those germs they’ll pick up from other mucky toddlers.

12 Weeks Pregnant Symptoms

It’s said that many women start to really enjoy their pregnancy as they enter into their second trimester. This is because they’re able to wave goodbye to their pesky early pregnancy symptoms and side effects which have plagued them in their first three months.

Unfortunately, as every woman and every pregnancy is different, this is not always the case. Additionally, you may still experience the below symptoms at 12 weeks pregnant.

Dizziness and feeling faint

The extra blood pumping around your body can cause you to feel light-headed, dizzy and even faint. To ease these symptoms, try and remember to stand up and sit down slowly and keep sugar levels up with regular (healthy) snacks. If you feel faint, make sure you take a seat and rest up as soon as possible.


Your lower blood sugar levels can also lead to headaches. Again, snacking can help keep your sugar levels stable. However, if your headaches persist, it’s worth consulting your doctor. They’ll also be able to advise on pregnancy-safe painkillers.


Although many women experience a new burst of energy in their second semester, you may still experience bouts of fatigue as your baby continues to grow.

Heightened sense of smell

You may notice that you’re still sensitive to certain smells and tastes at three months pregnant.

Bloating, indigestion and heartburn

This pesky progesterone has a lot to answer for. Increased levels of the hormone in your body can also cause bloating at 12 weeks pregnant. This is because it slows down the digestion process so that there’s more time to pass the nutrients on to your baby. However, in doing so, your growing uterus will squash and press onto your stomach and intestines. Your hormones also relax the valve between your stomach and esophagus, causing heartburn.

Your Body and Bump at 12 Weeks Pregnant

By three months pregnant, you may have a small baby bump. However, it is still normal not to be showing at this stage.

At 12 weeks, while your baby is the size of a lime, your womb is approximately grapefruit-sized and growing.

In the coming weeks, your uterus will push above your pelvic bone, which leads to a more prominent baby bump. In the meantime, with your waist thickening and appetite increasing, you may start to feel your clothes becoming snug. If so, it might be time to start shopping around for your maternity wardrobe.

Read: All of our favourite pieces from the Zara UK maternity collection

Ultrasound: 12-week Scan

This is where things get exciting. At 12 weeks you’ll be ready for your first of two very important scans, known as the ‘dating scan’.

Although often dubbed the 12-week scan, this can take place anytime between 10 and 14 weeks. At this appointment, a sonographer will carry out an ultrasound which will be used to give you an estimated due date.

The scan will also look at a few other things. These include:

  • Size of your baby – they’ll check your baby is growing and developing correctly.
  • Number of babies – at this scan you may find out you’re expecting twins (or more!!).
  • Heartbeat – this is usually the time you’ll be able to hear your baby’s heartbeat.
  • Vital organs – the sognographer will also make sure you’re baby’s organs are developing.

Read: Everything you need to know about the harmony test

For more information on development and milestones at every stage of your pregnancy, visit our pregnancy week by week page.

Read more: What is Cranial Osteopathy?

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