12 weeks pregnant: Pregnancy Symptoms & Baby Development

At 12 weeks pregnant, you’re about to enter your second trimester. Many pregnant women find that many unpleasant symptoms of their pregnancy start to ease as they come to the end of the first trimester, so you may find that you’re feeling better and more energetic¹.

At this point in your pregnancy, your little one’s rapid development continues. By now your baby has fully formed limbs and internal organs, and the placenta is taking over the job of nourishing your growing baby, who’s focus will now be on getting bigger.

From your baby’s development and what’s happening for you and your body, to the importance of omega-3 and 6 for a healthy pregnancy diet, let’s look at what you can expect at 12 weeks pregnant.

Your foetus is fully formed at 12 weeks pregnant. Each one of your baby’s limbs, muscles, bones and organs are now in place - including their sex organs². However, it’s still a little too soon to be able to tell what sex your baby will be, as this is unlikely to show up on an ultrasound scan¹.

Although you’re unlikely to feel anything at 12 weeks pregnant, your little one is moving around a lot in your womb, and you’ll be able to see their movements when you go for your scan².  Your baby can now move their legs and curl their fingers and toes³.

At this point, your baby is most likely getting all the nutrients they need from the placenta, which has taken over the job from the yolk sac (1). All that’s left for your baby to do now is grow.

At 12 weeks pregnant, your baby is around 5.4 cm long, and is about the size of a small plum¹. Their head is still very big in comparison to their body, but their tiny facial features are becoming more defined³.

Your baby’s eyelids are closed, and it won’t be until around week 28 of your pregnancy that they’ll start to open again. Amazingly, their unique fingerprints have already formed, and your baby’s milk teeth are sitting within the gums, ready to emerge³.  

The end of the first trimester is an exciting time, as it’s around now that you’ll be offered your first ultrasound scan by your healthcare provider. Whilst it’s your choice whether or not to go to your scans, it’s important to remember that they can help to ensure that you’re enjoying a healthy pregnancy, and to determine whether your baby has a health condition that may require medical attention⁴.

During your pregnancy, you’ll usually be offered two scans. The first is also known as the ‘dating scan’ because it will help to estimate your baby’s due date. It will be offered anywhere between 11 and 14 weeks of your pregnancy. During the appointment, the sonographer can also carry out a nuchal translucency scan (if you’ve chosen to have this) which forms part of the screening tests for Down’s syndrome⁴. The second scan, also known as the ‘anomaly scan’ will be offered at between 18 and 21 weeks⁴ and checks how your baby is developing physically.

If you have any questions or concerns at all, don’t hesitate to have a chat with your healthcare provider, as they’ll be able to tell you more about what to expect from your scans and your pregnancy healthcare in general.

Now that the placenta is doing the job of feeding your baby, the hormones in your body may start to settle down a little, leaving you feeling better and with more energy¹.

At the end of the first trimester, you may not yet have a baby bump or look as if you’re pregnant, especially if this is your first pregnancy. However, if you’ve had previous pregnancies however, you may be starting to show⁵.

You might notice that your waist is getting thicker at 12 weeks pregnant, and that your breasts are getting larger¹. Feeling hungrier? This is very common as you enter your second trimester, particularly if you’ve not had much of an appetite due to morning sickness¹.

Whilst you may find that some of the pregnancy symptoms you’ve experienced up to now have subsided, it’s not uncommon for others to kick in. From tiredness and fatigue to constipation and bloating, let’s look at some of those 12-week pregnancy symptoms.

And remember, if you’ve still not noticed any, that’s fine too, there’s no way to predict which symptoms (if any) you’ll get, and when.

There are no official guidelines about how much weight you should gain during your pregnancy. However, most pregnant women tend to gain around 10 -12.5 kg across their entire pregnancy, with most of that taking place partway through your second trimester (from approximately 20 weeks)¹⁶.

Most of this weight gain is made up of¹⁷:

• Your growing baby
• Amniotic fluid
• The placenta
• Additional water in the body
• Your breasts getting larger

At 12 weeks pregnant, if you’ve had your first scan, you may feel ready to tell your friends and family, as well as your employer, about your pregnancy. Give some thought to what your working life will look like, and the amount of maternity leave you intend to take.

By now, it’s also likely that you’ll have had your booking appointment with your midwife, who will have provided lots of helpful information about how to have a healthy pregnancy. If you haven’t had your booking appointment yet, be sure to check in with your healthcare provider.

Now is also the time to consider whether you wish to opt for screening tests to determine whether your baby has a higher risk of certain conditions, for example, Down’s syndrome². Your doctor and midwife are there to provide the information you need about the screening tests offered and provide any support that you may need.

Other things to think about include:

• Ensuring that you’re eating a healthy and balanced diet.
• Any supplements or prenatal vitamins that you should be taking to support a healthy pregnancy. 
• Reducing your caffeine intake and, if you’re a smoker, seeking advice and support around quitting. Both of these things will help you manage your blood pressure¹⁸.
• Considering whether you’d like to attend an antenatal class and seeing what’s available in your local area.