EXPLAINED: PREMATURE BIRTH AND ITS RISKS TO BABIES

Around 10 per cent of all pregnancies worldwide result in premature labour - defined as a delivery before 37 weeks.

When this happens, not all of the baby's organs, including the heart and lungs, will have developed. They can also be underweight and smaller.

Tommy's, a charity in the UK, says this can mean so-called preemies 'are not ready for life outside the womb'.  

Premature birth is the largest cause of neonatal mortality in the US and the UK, according to figures. 

Babies born early account for around 1,500 deaths each year in the UK. In the US, premature birth and its complications account for 17 per cent of infant deaths.

Babies born prematurely are often whisked away to neonatal intensive care units, where they are looked after around the clock.  

What are the chances of survival?

• Less than 22 weeks is close to zero chance of survival
• 22 weeks is around 10%
• 24 weeks is around 60%
• 27 weeks is around 89%
• 31 weeks is around 95%
• 34 weeks is equivalent to a baby born at full term