There are two peaks for maternal rubella to infect the fetus, causing embryopathy- first 4 weeks gestation ( risk 50%) and after 26 weeks (risk 75%) the former being responsible for most florid embryopathy.
Rubella embryopathy may end up as abortion. Neonatal manifestations include low birth weight, hepatosplenomegaly, icterus, hemolytic anemia, thrombocytopenic purpura, petechiae or maculo papular rash, and osteitis.
Congenital defects include cardiovascular malformations, microcephaly, cataracts and microphthalmia.
Late sequelae iclude deafness, mental retardation, thyroid disorders, diabetes mellitus, degenerative brain disease, infantile autism, etc.
Isolation of the agent is possible from throat swab, urine and CSF.
Additional tests include cord serum for IgM fluorescent antibody, paired maternal and cord sera for complement fixation, and neutralizing and hemagglutination inhibition titers.
The only foolproof means of prevention of congenital rubella is vaccination of the girls before puberty.