What is Congenital Rubella Syndrome?

Congenital rubella syndrome, or CRS, is a disorder that affects a baby in the womb when the mother is infected with the rubella virus. Possible signs and symptoms of CRS include deafness and heart and eye defects. The baby's mental and physical development also may be abnormal, and diseases such as diabetes may develop later in life. There have been fewer babies with congenital rubella syndrome following the introduction of the measles, mumps and rubella (MMR) vaccine, as the number of cases of rubella has fallen.

A congenital disorder is a health condition which exists at the time a baby is born. Syndromes are conditions which consist of a range of symptoms found together. In the case of congenital rubella syndrome, the symptoms are caused by the rubella virus damaging the baby, or fetus, in the womb, typically during the first three months, or first trimester, of pregnancy.

This first trimester is an important time for development of the fetus although the exact process by which the rubella virus injures fetal tissues is not fully understood. When the virus infects the fetus in the first trimester, problems almost always occur; infection during the fourth month or later leads to problems in only around a third of cases. If rubella infection strikes after the fourth month of pregnancy, congenital rubella syndrome is much less likely.

The three main symptoms of congenital rubella syndrome are deafness; eye problems, such as cataracts; and heart defects. Worldwide, rubella is the most frequent cause of babies being born deaf. The syndrome can interfere with fetal growth, resulting in babies being born underweight or prematurely, or the baby may even die before delivery.

Disorders of the brain and nervous system also can arise from congenital rubella syndrome, including brain infections, abnormal brain development, and a small skull. The liver can be affected as well, causing jaundice, or yellow-colored skin, and both the liver and spleen may be enlarged. On the skin, "blueberry muffin spots" may develop, which are purple or red areas that do not lose their color when pressed. There also may be blood problems such as anemia, and there can also be bone disorders. In later life, diseases such as diabetes and thyroid problems may occur.

Treatment of congenital rubella syndrome involves managing any disorders which are present. Surgery may be required to correct eye and heart defects, and sometimes deafness can be treated using cochlear implants, which are electronic devices that enable hearing. Prevention is important, and immunization against rubella decreases the number of people who contract the illness. This leads to fewer women contracting rubella during pregnancy and fewer cases of congenital rubella syndrome.