Updated October 2013
Multiple pregnancies and premature birth
Expecting twins, triplets or more? You can look forward to double - or triple or more - the joy once your babies are born, but carrying more than one baby also brings certain risks.
More babies means a shorter pregnancy
When you're expecting twins, triplets or more, it's called a multiple pregnancy. Carrying more than one baby means you are more likely to have a premature delivery.
More than half of twin pregnancies, and almost all triplets, are born at or before 36 weeks. Half of all twins are born before 37 weeks and weigh less than 5.5lb (2.5kg).
Risks and complications
If you have a multiple pregnancy, you will be at higher risk of many of the potential complications that can cause premature birth or lead to induction, including:
Premature delivery appears to be more common in pregnancies conceived through assisted reproductive technologies such as in vitro fertilisation (IVF) than in those conceived naturally and IVF increases the chance of multiple pregnancy.
In this section
The causes and problems of premature birth:
Your premature baby:
You can also read about
NHS Choices (accessed Sept 2011) Livewell, Twins and multiples, http://www.nhs.uk/Livewell/twins-and-multiples/Pages/pregnancy-risks.aspx
Levene MI (1991) Assisted reproduction and its implications for paediatrics, Archives of disease in childhood, Vol 66, p1-3