Infant defects resulting from a women’s infection with the rubella virus during the fist trimester of pregnancy.
Transplacental transmission of the rubella virus to a fetus, resulting in spontaneous abortion, stillbirth, or major birth defects of the heart, eyes, or central nervous system, including deafness. Women who become pregnant and have not received rubella immunization should be advised of the risk of fetal development of CRS. For unimmunized women who develop rubella in the first trimester of pregnancy, the risk of CRS may be as high as 85%. The risk decreases sharply after the eighth week of pregnancy, and is absent after the 20th week of gestation. Fetal infection can be determined by serial studies of the immunoglobulin gamma M and immunoglobulin gamma G rubella antibodies. Prevention of CRS consists of active immunization of all children and of women of childbearing age.