For most people, rubella (also called German measles) is a mild infection that poses no serious health risks. Most people who get the virus have a mild, brief illness that resolves without negative long term effects. Pregnant women, however, are the exception.
For women who are not immune, rubella infection during pregnancy poses a high risk of congenital birth defects and miscarriage or stillbirth. According to the March of Dimes, infection during the first trimester carries an 85% risk of birth defects. Infection from weeks 13 through 16 of pregnancy brings a 54% risk of defects, and infection at the end of the second trimester results in a 25% risk of birth defects. Infection in the third trimester is not likely to cause serious problems.
The term for birth defects caused by rubella infection during pregnancy is congenital rubella syndrome, and the syndrome might include blindness, hearing impairment, heart problems, mental retardation, or small head size, and other complications. Pregnancy loss can also occur.
Given that the numbers are so scary, it's normal to be worried if you believe you have been exposed to the rubella virus. Your doctor should be able to give you some advice on your risk of complications; most doctors test for rubella immunity as a part of standard prenatal care (if you had blood tests done at your first appointment, rubella immunity was most likely included). If you are immune, chances are you will be fine. If you are not immune, exposure can be risky and your doctor can give you advice on what to do if you believe you have been exposed.
Women who are not immune but concerned about rubella can ask a doctor about an MMR vaccine before getting pregnant. (Rubella is the "R" in MMR). To be on the safe side, doctors generally advise waiting a month after MMR vaccination before trying to conceive, although no study has documented any risk associated with accidental exposure to the rubella vaccine during pregnancy.
Source:
March of Dimes, "Rubella (German Measles)." Quick Reference: Fact Sheets Jul 2007. Accessed 4 May 2008.
