Rubella Infection - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x Rubella (German measles) is a single stranded RNA virus, which is transmitted by airborne droplets between close contacts. In the UK, the incidence of rubella infection has reduced dramatically since the introduction of the MMR vaccination programme. However, infection with rubella during pregnancy can have serious consequences for the fetus, and it remains an important diagnosis. In this article, we shall look the clinical features of rubella infection, its investigations, management and complications. By TeachMeSeries Ltd (2026) Fig 1- Negatively-stained transmission electron micrograph (TEM). Rubella virus virions can be seen budding from the host cell surface. Antenatal Screening Until recently in the UK, pregnant women were screened for rubella infection and immunity. Two tests were performed: IgM antibody – present in acute infection. IgG antibody – present following infection or vaccination. In cases where neither antibody was present, the woman was encouraged to seek rubella vaccination post-delivery (rubella vaccine is a live virus, and should not be administered whilst pregnant). From April 2016, Public Health England stopped routine screening for rubella in pregnancy – largely because of the success of the MMR vaccination programme. Clinical Features Maternal rubella infection is often asymptomatic. When they occur, the clinical features are non-specific, and include malaise, headache, coryza and lymphadenopathy. This can be followed by a diffuse fine maculopapular rash. The incubation period of rubella is 14-21 days. By TeachMeSeries Ltd (2026) Fig 2The fine maculopapular rash seen in rubella infection. Investigations In women where rubella infection is suspected, ELISA can be performed to measure rubella specific IgG and IgM: IgM antibody – present in acute infection. IgG antibody – present following infection or vaccination. Management Any pregnant woman with a positive rubella screen should be immediately referred to a fetal medicine specialist for counselling and further management. Maternal Rubella infection itself is self-limiting, and there is no treatment. Antipyretics can be given for fever. The woman should be informed that she is infective (i.e. able to pass on the virus), from 7 days prior to the onset of symptoms to 4 days after. Fetal The risk of vertical transmission to the fetus, and likelihood of developing congenital rubella syndrome is determined by the gestational age at the time of infection: Gestation Risk of Vertical Transmission Risk of Congenital Rubella Syndrome <12 weeks 90% 90%, with high likelihood of multiple defects 12-16 weeks 55% 20%, with single defects most common 16-20 weeks 45% 20% risk of deafness >20 weeks 45% No additional risk The recommended management varies according to the gestational age at infection: <12 weeks – high likelihood of defects, it is reasonable to consider a termination of the pregnancy. 12-20 weeks – prenatal diagnosis of fetal rubella infection required. This is usually performed by RT-PCR on amniotic fluid samples. If transmission to the fetus is confirmed, management options include termination of pregnancy or ultrasound surveillance to identify features of congenital rubella syndrome (although some features of CRS cannot be detected by ultrasound). >20 weeks – No action required. Congenital Rubella Syndrome Congenital rubella syndrome describes the neonatal manifestation of infection with the rubella virus during pregnancy. The clinical features can be classified into ‘present at birth’ and ‘late onset’. Present at Birth Auditory Problems Sensorineural deafness Cardiac Defects Pulmonary Stenosis, Patent Ductus Arteriosus, Ventricular Septal Defect Ophthalmic Defects Retinopathy, Congenital Cataracts Central Nervous System Abnormalities Learning disabilities, Microencephaly Haematological Thrombocytopaenia, Blueberry Muffin Appearance Late Onset Diabetes mellitus Thyroiditis Growth Hormone Abnormalities Behavioural Disorders By TeachMeSeries Ltd (2026) Fig 3Congenital cataracts, resulting from congenital rubella syndrome. Frequent questions What is rubella and how is it transmitted? Rubella, also known as German measles, is a single-stranded RNA virus transmitted through airborne droplets from close contacts. The incidence of rubella has significantly decreased in the UK due to the MMR vaccination programme. What are the clinical features of rubella infection in pregnant women? Maternal rubella infection is often asymptomatic, but when symptoms occur, they may include malaise, headache, coryza, lymphadenopathy, and a diffuse fine maculopapular rash. The incubation period for rubella ranges from 14 to 21 days. How is rubella infection diagnosed during pregnancy? Diagnosis of rubella infection in pregnant women is typically made through ELISA testing to measure specific IgG and IgM antibodies. The presence of IgM indicates acute infection, while IgG suggests past infection or vaccination. What are the potential risks of rubella infection to the fetus? The risk of vertical transmission and congenital rubella syndrome varies with gestational age at the time of maternal infection, with the highest risks occurring when infection happens before 12 weeks of gestation. This can lead to serious defects, including deafness and cardiac issues. What management options are available for pregnant women with rubella infection? Management depends on the gestational age at infection; for those infected before 12 weeks, termination may be considered due to high defect likelihood. Between 12 to 20 weeks, prenatal diagnosis is required, while no action is needed for infections after 20 weeks. Rate This Article