Rubella is also known as German measles. In children, rubella infection causes a mild rash on the face, swelling of glands behind the ears and in some cases swelling of the small joints and a low-grade fever. Most children recover quickly from rubella with no lasting effects. If a pregnant woman gets rubella, however, the results can be devastating. If she is infected during the first trimester of pregnancy there is a greater chance her child will have a birth defect such as blindness, deafness, heart defect, or brain damage.