Week 20 of Pregnancy

Written by Amina Hatia RM and medically reviewed by Marley Hall RM

Published on January 25, 2022
Live & Online 60,000+ Community

You’ve made it to the milestone of halfway through your pregnancy – wow! Lots happening this week for you in terms of appointments and checks, so be prepared for a busy and hopefully exhilarating week ahead. 

One of the big events this week is your 20 week or the official term- fetal anomaly scan. It’s the second routine scan of your pregnancy under NHS care and can actually be carried out anytime between 18-21 weeks.

Whilst it’s an incredibly exciting event to see your baby on a screen, ultrasound scans are firstly important clinical checks of the physical development of your baby – so be aware that your sonographer will be quite focused on carrying out measurements and those all-important checks.

At your 20-week scan, your sonographer will be looking in expert detail and carrying out measurements of all parts of your baby’s bones, heart, brain, spinal cord, face, kidneys and stomach. They will also be checking for 11 rare conditions listed below:

  • anencephaly
  • open spina bifida
  • cleft lip
  • diaphragmatic hernia
  • gastroschisis
  • exomphalos

This website provides you further information on each of these conditions:

Like your first scan, your 20-week screening scan is carried out in the same way as the 12-week scan – using a scanning probe and special gel over the skin of your bump to get images that will appear on a screen. It shouldn’t hurt at all, but you may find that the sonographer may need to apply a little pressure at times to be able to see clearly.

Don’t be surprised if your sonographer is initially quiet during parts of the scan, they will be concentrating on making sure they are carrying out all of the checks on your baby accurately – and you’ll find once they have completed their measurements, they will explain all the results to you in detail. 

The scan can take around 30 minutes but may take longer if your baby is being a little shy and needs cajoling into a different position.

Your sonographer may ask you if you would like to know the sex of your baby – but don’t hesitate to ask them if they haven’t mentioned it. Finding out the sex of your baby is not part of the scan checks, but your sonographer may share what they think it may be with you if you ask them to check and baby is in a position where they can see clearly.  

How big is my baby?

You’ll find out from your scan roughly how much your baby weighs and how long they are – remember, all babies are different and will vary in size. Nonetheless at 20 weeks your baby is the size of a juicy bell pepper, measuring in length about 25.6 cms, whilst weighing about 300 grams.

What happens in week 20 of pregnancy?

Well you’ve probably seen all the amazing changes and developments your baby has mastered during your scan, especially when compared to your previous scan at 12 weeks.

If you’re lucky you may have even picked up a wave or watched your baby sucking their thumb – which is just exceptionally cute to witness! Sucking their thumb, however, isn’t just cute – it’s an important skill that’s helps develop your baby’s sucking reflex that they will need for feeding – so practical, as well as cute and a comfort for your baby.

And that’s not all – your baby’s brain is also growing rapidly, with baby now being able to respond to different noises, such as your voice or different songs – so get singing and talking to baby if you haven’t already!

Week 20 pregnancy symptoms

Pigmentation changes in your skin because of pregnancy isn’t something that is often discussed but can affect quite a few people.  You may find that certain areas of your skin become darker, such as your nipples and the areola – the skin around the nipple. Any freckles, moles, or other skin marks may darken too.

Occasionally some women may find that in pregnancy patches of pigmentation appear on your forehead, cheeks, or neck. This is commonly referred to as the mask of pregnancy or chloasma. Pregnancy hormones are thought to be the cause and it may also run-in families too. If you are affected by chloasma try not to worry – it will fade away after your baby has arrived, though may take up to a year. Chloasma won’t affect your baby and can be managed with cover up solutions such as foundation or concealers.

Week 20 pregnancy tips

  • Get some good skincare routines in place for the remainder of your pregnancy – it’ll help you feel good about yourself and also ensure you are keeping your skin nice and supple.

  • Have you thought of what you are going to buy for your baby yet – prams, pushchairs, car seats, cots, cribs are all big purchases.  Think about what meets your needs the best – do you need a buggy that works best on city streets or are you looking for something that can manage country life.

  • Start thinking about where to get expert advice on all these decisions ahead – baby shops, department stores, services such as Which can all offer advice – but also think about the other decisions you will be making in the next half of your pregnancy about labour, birth and beyond and plan your antenatal classes in plenty of time!

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