What are the management and treatment guidelines for rubella infection in pregnancy?

Management and Treatment Guidelines for Rubella Infection in Pregnancy

There is no specific antiviral treatment for rubella infection during pregnancy, and management focuses on diagnosis, counseling, and prevention of congenital rubella syndrome through vaccination of non-immune women before pregnancy or postpartum.

Diagnosis of Maternal Rubella Infection

Laboratory Confirmation

• Serologic confirmation is essential as clinical diagnosis is unreliable 1
• Methods for confirming maternal rubella infection:
  • Detection of rubella-specific IgM antibodies (most common method) 2
    • Collect serum 1-2 days after rash onset
    • If negative, collect second specimen 5 days after rash onset
    • IgM typically detectable for 4-12 weeks after infection
  • Demonstration of significant rise in rubella IgG antibody titers 2
    • Acute-phase serum within 7 days of rash onset
    • Convalescent-phase serum at least 10 days after acute specimen
    • Both specimens tested simultaneously in same laboratory

Important Considerations

• False-positive IgM results may occur with:
  • Certain viral infections (infectious mononucleosis, cytomegalovirus, parvovirus)
  • Rheumatoid factor positive patients 2, 3
• For exposure without rash illness:
  • Obtain acute serum specimen as soon as possible after exposure
  • Collect convalescent specimen at least 28 days after exposure 2

Management of Pregnant Women with Rubella

Risk Assessment

• Highest risk of congenital defects occurs with infection in first trimester 1, 4
  • Up to 80% risk if acquired in first 12 weeks 4
  • Defects rarely occur after 16 weeks gestation 1
• Maternal infection does not always result in fetal infection 5

Prenatal Diagnosis of Fetal Infection

• Detection of rubella-specific IgM antibodies in fetal blood 3, 1
• Viral isolation from amniotic fluid or fetal tissue 3
• Prenatal diagnosis helps distinguish cases without fetal damage 5

Counseling

• Discuss risk of congenital rubella syndrome based on gestational age at infection
• Explain that no specific antiviral treatment exists to prevent transmission 5
• Provide information about potential congenital defects:
  • Eye defects (cataracts, glaucoma, pigmentary retinopathy)
  • Hearing impairment
  • Cardiac defects
  • Microcephaly
  • Growth retardation
  • Neurological abnormalities 3

Post-Exposure Prophylaxis

• Immune globulin (IG) after exposure:
  • Will not prevent infection or viremia
  • May modify or suppress symptoms
  • Not routinely recommended for post-exposure prophylaxis in pregnancy 2
  • May be considered only when a pregnant woman exposed to rubella would not consider pregnancy termination under any circumstances 2

Prevention of Congenital Rubella Syndrome

Prenatal Screening

• All pregnant women should be screened for rubella immunity at first prenatal visit 2, 3
• Laboratories should retain prenatal specimens until delivery in case retesting is needed 2

Postpartum Vaccination

• Vaccinate non-immune women immediately after delivery 2, 3
• Counsel women to avoid pregnancy for 3 months after vaccination 2, 3
• Breastfeeding is not a contraindication to vaccination 2

Management of Infants with Congenital Rubella Syndrome

Diagnosis

• Laboratory confirmation through:
  • Detection of rubella-specific IgM in cord blood 2, 3
  • Viral isolation from nasopharyngeal secretions and urine 2, 3
  • Documentation of persistent rubella antibody levels beyond 3 months of age 2, 3

Infection Control

• Implement contact isolation for suspected cases 2, 3
• Only personnel with confirmed immunity should care for these infants 2, 3
• Consider infants infectious throughout the first year of life unless nasopharyngeal and urine cultures are negative after 3 months of age 2, 3

Long-term Follow-up

• Monitor for delayed manifestations including diabetes mellitus, thyroid disease, and glaucoma 1
• Regular hearing, vision, and developmental assessments are essential 3, 1

Common Pitfalls to Avoid

• Confusing maternal non-immunity with active infection 3
• Overlooking the need for maternal vaccination postpartum 3
• Misinterpreting serologic results due to false positives or negatives 3
• Failing to implement proper isolation precautions for infants with CRS 3