Pregnancy information

Your baby at 21 weeks

By 21 weeks, your baby weighs around 350g.

From about this stage onwards, your baby will weigh more than the placenta, which, until now, was heavier than your baby. The placenta will keep growing throughout pregnancy, but not as fast as your baby.

Around this time, the baby becomes covered in a very fine, soft hair called lanugo. The purpose of this is not known, but it's thought it may be to keep the baby at the right temperature. The lanugo usually disappears before birth.

You at 21 weeks

Your womb will begin to get bigger more quickly and you'll really begin to look pregnant.

You may feel hungrier than before – try to stick to a balanced, healthy diet in pregnancy, and make sure you know what foods to avoid when you're pregnant.

Your baby at 22 weeks

Your baby is beginning to get into a pattern of sleeping and waking, which will not necessarily be the same as yours. When you're in bed at night, feeling relaxed and trying to sleep, your baby may be wide awake and moving about.

You at 22 weeks

Not everybody gets stretch marks, but if you do, they will probably start becoming noticeable when you're around 22 to 24 weeks pregnant.

They may appear on your stomach, breasts and thighs. At first they can be pink, red, purple or brown, depending on your skin colour. They may gradually fade into paler scars and become less noticeable.

Your breasts may start to leak a little pre-milk – this is normal.

You may also notice skin changes in pregnancy. Find out more about skin changes on our page about common health problems in pregnancy.

Your baby at 23 weeks

Your baby's lungs are not yet able to work properly, but they are practising breathing movements to prepare for life outside the womb.

Your baby gets all their oxygen from you via the placenta and will do so until they're born.

You at 23 weeks

You may develop piles (haemorrhoids). Piles are swellings containing enlarged blood vessels inside or around your bottom (the rectum and anus).

Piles can happen to anyone, pregnant or not, and can be very uncomfortable. They can happen when you're pregnant because hormones make your veins relax, but there are ways to ease piles in pregnancy.

Tiredness and lack of sleep are common in pregnancy. There are plenty of things you can do to help yourself sleep, including using pillows to support your growing bump.

Your baby at 24 weeks

By the time you're 24 weeks pregnant, the baby has a chance of survival if they are born. Most babies born before this time cannot live because their lungs and other vital organs are not developed enough.

The care that can now be given in baby (neonatal) units means more and more babies born early do survive. But for babies born around this time, there are increased risks of disability.

You at 24 weeks

You may get thrush in pregnancy. Having thrush when you're pregnant can be irritating but it will not harm your baby. Your midwife can recommend treatment.

See your doctor or midwife if you have any pain when you pee. This could be sign of a urinary tract infection (UTI) that needs treating.

You can find more information on pregnancy in the 'Your Pregnancy and Birth book'.

Last Updated: 21/07/2023 10:55:58
The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website