Your week by week guide on what to expect when you're expecting...

20 – 24 Weeks Pregnant

When you are 20 weeks pregnant the baby will start to be measured from head to toe instead of crown to rump as their legs will no longer be curled up so tightly.

At 21 weeks they will be approximately 25 cm long.  Their legs will be strong and you will probably feel them as they kick.

At 22 weeks a boy’s testes will be descending into his scrotum.

At 23 weeks your baby’s hearing will be more developed as the bones in their middle ear have hardened.

By 24 weeks the baby will be about 30cm long.  Their taste buds will be developing and they may notice the change in the taste in his amniotic fluid when you eat or drink something strange!

20 Week Scan

You may feel anxious as you approach your 20 week scan.   This is usually done between 20-22 weeks.  This is an important milestone for most mothers as it marks the halfway point in their pregnancy.  Many women can feel excited but nervous or apprehensive about this scan and its possible results

What to Expect at the 20 Week Scan

Measurements of the baby will be made and predictions will be made about its growth over the next 20 weeks. The sonographer will look for the position of the placenta and check that the levels of the amniotic fluid are correct. It is also an opportunity to look at blood flow through the placenta and the baby as a way of screening for any possible tendency to pre-eclampsia or inter-uterine growth restriction (babies that are not growing well in the uterus).

The sonographer will have an excellent view of the spine and skeleton in order to rule out spina bifida. They will also be able to see the internal arrangements of brain and heart and watch the bladder performing,

The scan presents a unique opportunity to take a detailed look at the baby’s anatomy and should enable the sonographer to perform a detailed scan of baby’s anatomy picking up most significant anatomical abnormalities if there are any present.

If any abnormalities are found, you will be referred to fetal medicine specialist for further imaging and discussion on what happens next.

For many, the 20 week scan is a source of great excitement as it is the moment when you can find out the sex of the baby!  Some hospitals do not offer this service as part of the 20 week scan – so if this is the case and you are keen to find out the sex of the baby you will have to make your own private arrangements to do so. 

Many people do not want to know the sex of their unborn child, preferring to keep it a surprise until the birth. (some people say it helps them to keep focused during the birth as they cannot wait to see if they have been carrying a boy or a girl).

The Sonographer should always ask you if you would like to know the sex of the baby, and if you express your wishes for it to be kept a secret, he or she will refrain from letting you know what it is!  The sonographer may even go so far as advising you to look away when they are looking at the baby’s genitals in case you see something that gives it away! But do not worry too much, many people with untrained eyes cannot make out much on the blurred screen, especially if the baby is a wriggler!

After your scan you will see your midwife for a check-up where you will review any results.

The Baby’s Movement

You should now be feeling the baby move quite frequently, randomly, every day.  You may not notice a pattern but you may feel more movement in the evenings, this is probably due to the fact that this is the time when you are most sedate.  If you are busy during the day, small movements and kicks may go unnoticed.

Stretch Marks

For some first time mothers, your bump may just be starting to grow but may still be undetectable to outsiders.  Your tummy may feel itchy as it starts to grow and the skin starts to stretch.  You can apply your usual body lotion to help keep the skin hydrated and more elastic as it stretches.

Whether or not you get stretch marks during your pregnancy will depend entirely upon your genetics.  If your mother or sister had stretch marks during their pregnancy, the chances are that you will too.  Lotions or potions will sadly not keep these marks at bay but some may help with the discomfort of your skin stretching and keep your skin moisturised.  Some creams and oils are designed to help with the texture and pigment of your skin and can go some way to minimise the appearance of stretch marks and help them to fade.

Weight Gain

If you have not already, it is likely that you will be starting to put on some weight at this stage in your pregnancy.

How much weight you put on will depend on a number of things such as your pre pregnancy weight and height, your build, your propensity to put on weight and your diet and attitude towards exercise throughout the pregnancy. 

Gone are the days where you were advised to eat for two!  Current advice suggests you continue to eat normally whilst of course listening to your body- if you are hungry then you must eat, but do not eat a cheeseburger for yourself and then one for the baby!

It is important to note that as long as you are staying healthy and as active as you can, you should not be concerned about your weight gain.  It is a natural and necessary part of being pregnant and you definitely should not try to diet at this time.  Your doctor or midwife may not even weigh you during your pregnancy unless he or she is worried that you are over or under weight.

For fun, you can check out a pregnancy weight gain calculator.  Remember to take the results with a pinch of salt as no one can predict how much weight you will put on.


You may start to pee a lot at night time.  This is as a result of your growing uterus exerting pressure on your bladder. Kidneys are working 50% more and producing more urine.

You may be suffering from Indigestion or Haemorrhoids which can be very irritating, we have lots of information and tips on how to deal with these problems.

Your MATB1 can be signed from 20 weeks.  This is the certificate signed by your midwife or doctor to show your expected date of childbirth.  This is usually required by employees and is needed in order to claim Statutory Maternity Payment, or Maternity Allowance.

Read about the next stage, 24 – 28 weeks.

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Want to know what to expect week by week in pregnancy? Got some burning questions for what you can and can’t do with a bun in the oven? Want to find out what might happen during your labour… it’s all in our free guides! 

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