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Pregnancy health centre

15 weeks pregnant

WebMD Medical Reference
Medically Reviewed by Dr Rob Hicks


How is your baby growing at 15 weeks?

The foetus is now 9–10cm from head to bottom (crown to rump) and weighs about 75g. The body is covered in the fine hair known as lanugo. The eyebrows and hair on the scalp may also start to grow, but they may not be the same colour and texture as the hair that your baby has after birth.

Your baby's ears may still be set slightly too low on the head but it won't be long before they reach their final positions. The ears may now be functioning – the first things your baby may hear will be noises from your digestive system, your heart beating, your voice and muted noises from outside of your body. Although your baby's eyes will still be closed, they may be able to detect bright light from the outside world.

The legs will now be growing longer than the baby's arms, and skeletal and muscle development will continue. The baby will still be practising all sorts of movements with his or her head, mouth, limbs and toes and fingers.

How are you changing in week 15?

As your abdomen continues to expand you may not be able to put off switching to maternity clothes. There's a good chance that you may feel like you're on an emotional roller coaster and not only due to changes in hormones. Seeing how your waist is expanding can bring on the reality of childbirth and being responsible for a newborn baby – and it's natural that these can be scary prospects for first-time mums-to-be as well as for mums who are already caring for older children.

Some pregnant women become a bit more forgetful and struggle to concentrate. Fatigue and thinking about the pregnancy can contribute to forgetfulness in the earlier stages of pregnancy, but physical changes in your brain may be the cause in the later stages of pregnancy. Although parts of your brain will increase while you’re pregnant, the total size of your brain will decrease, especially in the third trimester. So be prepared to be forgetful in the next few months and to have a difficult time in processing new information. Before you forget, it might be a good idea to have an organiser to help you remember appointments and tasks that need doing. Your brain should return to its normal size by around 6 months after you give birth.

You may think your hair is growing thicker, but your hair isn't any thicker – what is actually happening is that an increase in oestrogen in your body is making fewer hairs fall out during pregnancy, so you are keeping more hairs on your head. The same is true of your eyelashes and eyebrows. However, several weeks after the baby is born, it's likely you'll notice an increase in hair loss when you wash your hair. Don't panic – you're not going bald but just losing the extra hairs that did not fall out during pregnancy. Your hair is just returning to its normal pre-pregnancy state.

You may notice that your nose is getting a bit congested or stuffy and you may even have nosebleeds, especially after the first trimester. This is sometimes referred to as pregnancy rhinitis. Once again, hormonal changes that widen blood vessels and an increased blood supply are behind these problems. Your gums may bleed for these reasons too when you brush your teeth.

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