rubella syndrome, fetal

rubella syndrome, fetal A constellation of abnormalities caused by infection of a mother with the rubella (German measles) virus before the birth of her baby. The syndrome is characterized by mental retardation and multiple birth defects, including abnormally small head, cataracts, glaucoma, abnormally small eyes, and cardiovascular malformations. Deafness is common. The risk of congenital defects in the fetus is greatest when the mother is infected with the virus during the first 16 weeks of pregnancy. Also known as congenital rubella syndrome.