Congenital rubella syndrome is a spectrum of congenital abnormalities that result from primary maternal infection with the rubella virus. It falls under the TORCH group of infections.

It is important to note that reinfection/reactivation of maternal infection has a significantly lower risk of fetal anomalies than compared to primary infection.

Rarely congenital rubella syndrome can result in progressive disease known as progressive rubella panencephalitis ⁸. 

Clinical presentation

Features can include:

• congenital sensorineural deafness

• congenital cataract formation

• congenital cardiac anomalies: particularly

  • ventricular septal defects (VSD)

  • tetralogy of Fallot

• intellectual/learning disabilities

• microcephaly

• intra-uterine growth restriction (IUGR)

The first three clinical features were classically termed the Gregg syndrome.

Pathology

The rate of congenital infection is worst during the 1^st trimester (particularly during the first 6 weeks). 

Serological markers

• maternal rubella specific IgG

• maternal rubella specific IgM

False positive results of IgM antibodies are common. It must be followed with IgG avidity testing to ensure if the infection is recent or not ⁷.

Radiographic features

Ultrasound

Sonographic findings are often not specific and a normal scan cannot absolutely exclude an infection. Features that may be seen include

• evidence of hydrops fetalis if severe

• evidence of a congenital cardiac anomaly (e.g. ASD and VSD) ⁸

• evidence of intra-uterine growth restriction

• sub-ependymal cysts: on cranial ultrasound ²

CT

Brain manifestations ⁸:  

• small head circumference/microcephaly

• periventricular calcifications

• white matter hypodensity

• ventriculomegaly