Rubella (also known as 'German measles') is a viral infection that used to be common in children. It is usually a mild infection.
Rubella's incubation period is between 2 and 3 weeks with its infectious period lasting from 1 week before the rash first appears until at least 4 days after it's gone.
It's recommended children are immunised against rubella as part of their routine childhood immunisation program.
What causes rubella?
Rubella is caused by the rubella virus that's spread through personal contact, or by coughing and sneezing. Once you have had rubella then you normally develop a lifelong immunity against further infection.
Rubella is best prevented by the MMR vaccination.
Congenital rubella syndrome
If a pregnant woman who does not have immunity to rubella (either due to previous infection or vaccination) catches the rubella virus, then the virus can be passed on to her unborn baby.
The virus can disrupt the development of the baby, causing a series of birth defects that are known as congenital rubella syndrome (CRS).
The risk of CRS affecting the baby and the extent of the birth defects it causes depends on how early in the pregnancy the mother is infected. The earlier in the pregnancy the greater the risks. CRS can include hearing and visual impairments, developmental delay and other problems in the baby.
As many as 9 out of 10 babies whose mother caught rubella during the first 10 weeks of pregnancy will have CRS, with multiple birth defects. After 20 weeks there is no risk of the baby developing CRS.
Last reviewed: July 2017