23 weeks pregnant: your guide to baby’s development and your body

There’s lots going on for you and your baby at 23 weeks. While your little one grows and their senses continue to develop, you might be noticing symptoms like backache and feeling warmer than usual.

Here we’ve got everything you need to know at 23 weeks pregnant, from what’s happening inside your womb to tips on staying well. Let’s have a look.

Reviewed by Sammy, a registered NHS midwife with a background in neonatal nursing, dedicated to providing compassionate, evidence based care to women and families throughout pregnancy, birth and the postnatal period.

At 23 weeks pregnant, you’re just under 6 months pregnant and roughly two-thirds of the way through your pregnancy. 

By now, you’ve probably started to feel your baby moving around inside your bump. They’re starting to get into a regular pattern of sleeping and waking now, which, unfortunately, might not be the same as yours! It’s normal to feel your baby wide awake and moving around while you’re trying to get some rest¹.

Your baby (or 23-week foetus) now measures about 29cm from their head to their heel, which is about the size of a large mango².

Your baby can hear quite well now. They’re listening to sounds inside your body, like your heartbeat and rumbling tummy, as well as sounds from the outside world, like music and voices. Talking, reading and singing to your bump can be a really lovely way to bond with your baby at 23 weeks³.

Have you noticed any of these 23-week-pregnant symptoms?

Back pain is very common in pregnancy, especially as your bump gets bigger and puts more pressure on your lower back. If you’re getting a lot of back pain, try not to arch your back when you’re standing or sitting, and get as much rest as you can⁴.

The different hormones and increased amounts of blood whizzing around your body can mean that you feel warmer than usual during pregnancy. It can help to stick to loose, breathable clothing and to carry a handheld fan with you when you’re out and about⁵.

You might also feel a little faint during pregnancy, especially if you stand up too quickly. Try to move slowly when you’re changing positions, and take it easy if you do start to feel dizzy – the feeling should pass fairly quickly⁵.

Your body is getting ready for breastfeeding now, and might be starting to produce your first milk, which is called colostrum. Colostrum is thick and golden yellow, and you might notice that it begins leaking from your nipples from around week 16 of your pregnancy^6,7.

Towards the end of your pregnancy, you might want to collect your colostrum to feed your newborn baby, but for now, you can pop a bit of tissue or breast pad in your bra to soak it up.

You might hear people talking about ‘baby brain’ – where they feel more forgetful while pregnant. There’s no actual evidence that baby brain really exists, but other pregnancy symptoms, like tiredness, might give you a little brain fog⁸. Be gentle with yourself if you are getting forgetful – you probably have a lot on your mind!

Your 23 weeks pregnant bump is growing along with your baby. Soon, you should start going to sleep on your side instead of your back to avoid complications with your pregnancy. Don’t worry if you wake up on your back during the night – you can just roll onto your side again³.

You should have been offered the whooping cough vaccine at your 20-week ultrasound appointment, but you can have it any time from 16 weeks to 32 weeks pregnant².

Having the vaccination while you’re pregnant helps protect your baby from this dangerous condition while their immune system is still developing². You can get your whooping cough vaccine at the same time as your flu jab – so that's one less thing to think about.

Legally, you have to let your employer know that you’re pregnant at least 15 weeks before your due date, which is around 25 weeks. So, if you haven’t already, now’s a good time to let your work know that you’re expecting².

It also means you’ll get maternity rights and be able to go to your antenatal appointments during paid work time.

Eating a healthy, balanced diet is a good way of making sure you and your baby are getting all the nutrients you need during pregnancy. Make sure you’re getting a wide variety of foods every day, including lots of fruit and vegetables⁹.

Exercising during pregnancy can help your body cope with the changes to come in your second and third trimesters, and to prepare for labour. Aim for about 150 minutes of exercise a week – even a brisk walk can do wonders¹⁰.

Keep going with your pelvic floor exercises too, to help strengthen the muscles there for later pregnancy, labour, and beyond. Aim for three sets of eight squeezes per day¹⁰. You could do them after meals to help you remember!

Your skin is more sensitive to the sun during pregnancy, so it’s even more important to protect it. Wear a high-factor sunscreen when you’re out and about, even when it appears cloudy, and choose spots in the shade if you’d like to sit outside on sunny days².

You’ll have regular antenatal appointments during your pregnancy to check that you’re healthy and your baby’s developing well

But if you experience any of the symptoms below, you should call your midwife, maternity unit or doctor straight away to get checked out.

If this is your first pregnancy, it’s normal to not feel your baby’s movements until after week 20, but you should feel your baby moving every day from 24 weeks pregnant, right up until you give birth¹¹. From week 28 onwards, you should notice your baby has regular patterns of moving and sleeping. 

Your baby's movements are telling you that they’re happy, so it’s really important to monitor them and call maternity unit right away if you have any concerns¹².

If you notice any of these signs of premature labour before 37 weeks, call your midwife or maternity unit¹³:

• Regular contractions that get more intense as time goes on
• Pains that feel like period cramps
• Fluid trickling or gushing from your vagina (this could be your waters breaking)
• Backache that’s not normal for you

Ask for an urgent GP appointment or call 111 if you have symptoms of a urinary tract infection (UTI)¹⁴:

• A pain or burning feeling when you have a wee
• Blood in your urine
• Having the urge to wee more often
• A high temperature

You might notice an increase in vaginal discharge when you’re pregnant, which usually looks thin and either clear or milky white (15)[sa35.1]. If your discharge looks greyish-white, becomes very watery, or smells strongly (particularly after sex), it could be a sign of a  condition called bacterial vaginosis¹⁶.

Let your GP or midwife know if you notice discharge that’s strange for you.

Bleeding from your vagina can be caused by changes to your cervix, but it can also be a sign of something more serious. If you have any vaginal bleeding, contact your midwife or GP straight away¹⁷.

Some aches and pains are normal in pregnancy, but you should call your maternity unit or doctor if you experience any of the following:

• A splitting headache, especially if you also get blurred or flashing vision¹⁸
• Sudden swelling in your hands, feet, or face¹⁸
• Stomach pain that doesn’t go away after resting for 30-60 minutes¹⁹