15 weeks pregnant: baby's development, itchy skin and baby brain

Your baby is about the size of a small pear.

Your baby’s development this week  

Your baby’s hearing is developing and from around now they might be able to hear your voice, the comforting sound of your heartbeat and muffled sounds from the outside world.

They might also start to sense bright light outside your tummy.

This week your baby might start to get hiccups every now and again. Later in your pregnancy, you’ll probably be able to feel little rhythmic flutters when your baby gets hiccups.

You may not be aware of your baby’s movements yet – most women start feeling them at around 18 weeks. Try to get to know your baby’s pattern of movements when they start. Your baby moving is a sign they are well. Baby hiccups don’t count as baby movements.

Your pregnancy symptoms in week 15

Itchy skin

Is your skin feeling itchy on your growing bump? This is probably caused by your skin stretching. If so, it’s nothing to worry about. You could try massaging some unscented moisturiser into the skin.

You might also notice stretch marks. These are not harmful and don’t cause any medical problems.

Severe itching, particularly on hands or feet could be the sign of a serious pregnancy complication called intrahepatic cholestasis of pregnancy (ICP). Find out more about the symptoms of ICP.


If you have any bleeding during your pregnancy, with or without pain, it’s very important to get it checked out. Contact A&E or your hospital maternity unit immediately. 

Find out more about symptoms that need checking.


Pregnant women often get thrush because of hormonal changes. Thrush is a yeast infection that can cause a white discharge, itching soreness and redness around the vagina.

This can be uncomfortable, but there is no evidence that thrush can hurt your baby. Speak to your midwife or GP about treatment.

Baby brain

Some women find they become forgetful, can’t concentrate or are more absent-minded during pregnancy. This is often called baby brain. Research on the existence of baby brain is mixed. Some studies have shown that pregnant women have worse memories or decision-making skills. But it may simply be that pregnant women are more forgetful because they’re not sleeping well, feeling emotional and have a lot on their minds!

Whatever the reason, it may help to make lists of things to do, find ways to relax and try to sleep well.

Are you also getting headaches, cramps, swollen feet or indigestion? Here’s our guide to 10 common pregnancy complaints (and how to avoid them).

Try Tommy's 'Your healthy pregnancy tool'

What to do in week 15

Keep moving

Being active during pregnancy will boost your health – and it’s good for your baby, too. Now that your bump is becoming more obvious you may feel as if you need to protect it more, but it’s safe to exercise right up to your due date if you feel okay.

There are a few types of exercise to avoid, such as contact sports, but it’s fine to continue with most of the exercise you did before pregnancy.

If you weren't very active before your pregnancy, it's not too late to start. Even going for a walk can help. Here are some ideas for exercise in pregnancy.

“Yoga was fab. It really helped. My labour was amazing and quick and I'm sure it was down to great yoga instruction.”

Taking sick leave during pregnancy

If you need to take time off work for a pregnancy-related illness, it doesn’t count towards your sickness record.
If your manager usually provides sick pay, you will still be entitled to this. If your company doesn’t offer sick pay you can apply for statutory sick pay.

Find out more about a working pregnancy.

1. NHS. You and your baby at 15 weeks pregnant https://www.nhs.uk/pregnancy/week-by-week/13-to-27/15-weeks/ (Page last reviewed: 13 October 2021 Next review due: 13 October 2024)

2. Kingston Hospital NHS Foundation Trust. (2015) https://kingstonhospital.nhs.uk/wp-content/uploads/2019/12/fetal-movements-leaflet-webiste-version-pdf.pdf

3. NHS. Itching and intrahepatic cholestasis. https://www.nhs.uk/pregnancy/related-conditions/complications/itching-and-intrahepatic-cholestasis/ (Page last reviewed: 2 August 2019 Next review due: 2 August 2022)

4. NHS. Stretch marks in pregnancy. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/stretch-marks/ (Page last reviewed: 2 August 2019 Next review due: 2 August 2022)

5. NHS. Thrush. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/thrush/ https://www.nhs.uk/pregnancy/keeping-well/whooping-cough-vaccination/ (Page last reviewed: 1 April 2021. Next review due: 1 April 2024) Accessed: September 2021

6. Davies SJ, et al. (2018) Cognitive impairment during pregnancy: a meta-analysis. Med J Aust. 2018 Jan 15;208(1):35-40. doi: 10.5694/mja17.00131. PMID: 29320671.

7. NHS. Exercise in pregnancy. https://www.nhs.uk/pregnancy/keeping-well/exercise/ (Page last reviewed: 20 January 2020. Next review due: 20 January 2023)

8. Maternity Action. Sickness during pregnancy. https://maternityaction.org.uk/advice/sickness-during-pregnancy-and-maternity-leave/

Review dates
Reviewed: 11 July 2022
Next review: 11 July 2025