Rubella can be harmful to developing babies if their mothers become infected — especially during the first 10 weeks of pregnancy. Rubella infection during pregnancy can lead to a condition called congenital rubella syndrome (CRS). This syndrome can cause a range of birth defects. About 9 out of 10 babies, born to people who catch rubella during the first trimester of pregnancy, become affected by CRS. Birth defects associated with CRS include: low birthweight cognitive impairment hearing loss heart problems eye problems, such as cataracts Rubella vaccination is not recommended during pregnancy. If you are planning a pregnancy, see your doctor for a pre-conception health check. This usually includes making sure that you are immune to infections like rubella. Your doctor will check your vaccination history and sometimes refer you for a blood test. It is also a good opportunity to ask about any vaccines recommended for you before you try to conceive.