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Pregnancy health centre

27 weeks pregnant

WebMD Medical Reference
Medically Reviewed by Dr Rob Hicks


How is your baby growing at 27 weeks?

Your baby should measure about 36.5cm from head to toe and weigh around 875g. Your baby's body is getting plump and muscle tone continues to develop. At about two-thirds of the way through pregnancy, your baby now looks much like he or she will do at birth – with hair, eyebrows and eyelashes – albeit a bit smaller. Your baby’s eyes should now be opening and closing.

As your baby is gaining in size, his or her brain continues in becoming increasingly active. The smooth surface is now developing the characteristic grooves of a mature brain. Some experts think that dreams may start in week 27.

Babies often have bouts of hiccups that last for a few moments at this stage, which you may feel as gentle rhythmic jerking movements.

If your baby was born in this week, he or she will have an 85% chance of survival, with medical help. The lungs are still immature at this stage, but they would be able to function with intervention. However, the liver and immune system will be in a weak state and your baby will need to be in an incubator.

How are you changing in week 27?

Your bump will be quite noticeable by this week. As your womb continues to expand, you may notice stretch marks if you have not already. The top of your womb will be near your ribcage, which can cause shortness of breath. About 75% of pregnant women will experience shortness of breath during pregnancy. In early pregnancy it may be because the hormone progesterone affects the way your body absorbs oxygen.

Your ribcage will move up and outwards to increase your lung capacity, allowing you to breathe at the same rate as you did before you got pregnant, but you will need to take deeper breaths. Some mums-to-be are more sensitive to these changes than others. As you progress through the last few months of pregnancy, the growing baby and womb will press upwards, which will put increasing pressure on your lungs – especially if you are carrying your baby in a high position.

What you need to know in week 27

If this is a first pregnancy, the shortness of breath may ease as the baby drops down in the pelvis at about week 36 - this happens towards the end of pregnancy if you've been pregnant before. It will take a few months after you give birth for your hormones, ribcage and breathing to return to normal.

While being short of breath is common during pregnancy, if your heart is racing or has an irregular beat, you feel severely short of breath, have chest pain or are struggling to breathe at night or when lying down, contact your GP or midwife straight away.

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