Congenital rubella

Background

Pathophysiology

• Transplacental transfer of rubella virus occurs during viremia, which peaks about 5 to 7 days following infection of mother
  • Mother may be asymptomatic

Clinical Manifestations

• Spectrum of disease, which includes intra-uterine fetal demise, preterm delivery, and the congenital rubella syndrome
• Severity depends in part on timing of infection
  • Up to 8 weeks gestation: 20% chance of spontaneous abortion
  • Up to 10 weeks: 90% chance of congenital rubella syndrome (severe defects)
  • 13-18 weeks: 10-20% chance of hearing loss and retinopathy
  • Congenital defects are unlikely if infection happens after 18 to 20 weeks gestation
  • Intra-uterine growth restriction is likely only effect in third trimester
• Most children are asymptomatic at birth, but can develop signs and symptoms after several years

Congenital rubella syndrome

• Sensorineural hearing loss (most common findings), blueberry muffin rash (from extramedullary hematopoiesis), cataracts, glaucoma, congenital heart disease, and cognitive defects
• Low birth weight, thrombocytopenic purpura, hepatosplenomegaly, meningoencephalitis, retinopathy, patent ductus arteriosus, pulmonary stenosis, developmental disorders, cryptorchidism, inguinal hernia
• By the second decade of life, it can cause a progressing, fatal panencephalitis