Is it safe to be around someone with fifth disease (erythema infectiosum) while pregnant?

Management of Fifth Disease Exposure During Pregnancy

Pregnant women who are exposed to fifth disease (erythema infectiosum) should be tested for parvovirus B19 immunity, and if non-immune, should receive close monitoring with serial ultrasounds to detect potential fetal complications.

Understanding Fifth Disease and Pregnancy Risks

• Fifth disease is caused by parvovirus B19 and presents as "slapped cheek" rash in children, but can have serious implications for pregnant women who lack immunity 1
• Approximately 50% of pregnant women are already immune to parvovirus B19 from previous exposure, providing protection against new infection 2
• The rate of vertical transmission during maternal infection is estimated at 33-51%, with fetal complications occurring in approximately 3% of infected pregnant women 1, 3

Initial Management After Exposure

1. Determine immune status immediately:
   • Order both IgM and IgG antibody testing for parvovirus B19 1
   • If IgG positive but IgM negative: Patient has previous immunity and no risk to pregnancy 4
   • If IgM positive: This indicates acute infection requiring close monitoring 1
   • If both IgG and IgM negative: Patient is susceptible and requires follow-up testing if symptoms develop 3

Management of Non-Immune Pregnant Women

• High-risk occupations include teachers, daycare workers, and mothers of school-aged children 3
• Timing matters: Fetal complications including hemolysis, anemia, hydrops fetalis, and fetal loss are more frequent when maternal infection occurs before 20 weeks gestation 1
• Monitoring protocol for confirmed infection:
  • Referral to maternal-fetal medicine specialist or high-risk obstetrics 3
  • Serial ultrasound examinations every 1-2 weeks for 8-12 weeks after exposure to monitor for signs of fetal anemia or hydrops fetalis 4
  • If fetal hydrops is detected, intrauterine fetal blood transfusion may be considered at tertiary care centers 2

Special Considerations

• The risk of serious fetal complications is relatively low (3%) even with confirmed maternal infection 1
• Parvovirus B19 infection follows seasonal patterns with higher prevalence in late winter and early spring in temperate climates 3
• No specific antiviral treatment exists for parvovirus B19 infection; management focuses on monitoring and treating complications 2
• If fetal hydrops is detected, prompt referral to a center capable of performing intrauterine transfusion is essential as this intervention can significantly improve outcomes 3

Prevention Strategies

• Good hand hygiene practices are essential, especially after contact with children who may be infected 3
• Pregnant women in high-risk occupations should be particularly vigilant during outbreaks 4
• Consider temporary reassignment of duties for non-immune pregnant women working in settings with known outbreaks, particularly before 20 weeks gestation 3