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Key messages

  • Parvovirus can be transmitted across the placenta posing a potential threat to the fetus.
  • Vertical transmission is about 50 per cent. 
  • Consult with a perinatal infectious disease specialist. 
  • Fetal infection should be managed by a perinatologist.

Please note that all guidance is currently under review and some may be out of date. We recommend that you also refer to more contemporaneous evidence in the interim.

Human parvovirus B19 is a small non-enveloped virus that contains single-stranded DNA. It is responsible for several clinical syndromes.

Normal transmission is presumably by the respiratory route via droplet aerosol.

Most children have encountered the virus by their teenage years, but those who escape infection as children are susceptible as adults.

Pregnant women who are exposed should be informed of the risks to the fetus and offered serological testing.

Clinical manifestations

Fetal infection

Clinical features of fetal infection with parvovirus include:

  • Primary maternal infection has been associated with non-immune fetal hydrops and intrauterine fetal demise; there is no correlation between severity of maternal illness and that of the fetus.
  • Onset of hydrops usually 2-17 weeks (average 5 weeks) after maternal infection
  • Fetal deaths usually occur four to six weeks post infection but have been reported up to 12 weeks after B19 infection.
  • The attack rate for severe fetal disease (hydrops) is approximately 3 per cent following infection between 9 and 20 weeks.
  • Infections occurring beyond 18 weeks have been associated with anaemia.
  • B19 virus has been detected in cardiac tissue causing myocarditis, and can also cause fetal hepatitis with severe liver disease.

The pathogenic sequence in transplacental transfer of B19 virus: 

  • infection of RBC precursors  
  • arrested RBC production
  • severe anemia 
  • congestive heart failure
  • oedema. 

This is a condition managed by a perinatologist. 

Erythema infectiosum (fifth disease)

  • Most common manifestation of B19 infection.
  • A benign, self-limiting exanthematous illness of childhood.
  • The hallmark is a characteristic ‘slap cheek’ rash.

Parvovirus - slapped cheek rash 
Figure 1: Slap cheek rash

  • The rash spreads rapidly to the trunk and proximal extremities as a diffuse macular erythema.
  • The palms and soles are spared and the rash tends to be more prominent on extensor surfaces.
  • Central clearing of macular lesions occurs promptly giving the rash a lacy, reticulated appearance.
  • The rash resolves spontaneously without desquamation but tends to wax and wane over one to three weeks.
  • Individuals with chronic haemolytic conditions may experience transient red cell aplastic crises.
  • Arthritis and arthralgia of small joints may complicate fifth disease or be the sole clinical manifestation of infection.
  • Chronic infection may occur in the immunocompromised host causing chronic anaemia or complete marrow suppression.


  • Measure serum IgG and IgM levels.
  • IgM is detectable within 1-3 weeks of exposure and begin to fall by two to three months after infection.
  • IgG appears a few days after IgM and may persist for years.
  • Viral antigens may be directly detected in tissues by radioimmunoassay, ELISA, immunofluorescence, in situ nucleic acid hybridisation, or PCR.

Treatment of parvovirus infection

  • Levels of haemoglobin < 5 g/dL are considered to warrant in utero transfusion and are often associated with hydrops.
  • Hydrops should be managed by a specialist with experience in intrauterine transfusion. Limited data from several reviews indicate the following outcomes
  • Treatment is generally supportive.
  • There are case reports of successful use of Intravenous gamma globulin (IVIG) in patients with severe hematologic disorders.
  • IVIG prophylaxis may be considered in immunocompromised patients exposed to B19 infection.
  • IVIG is not currently recommended for prophylaxis in pregnancy.

Management of pregnant women at risk for parvovirus exposure

  • Pregnancy should be monitored by repeated ultrasound examination to detect fetal anaemia. Anaemia is suspected if the blood flow in the middle cerebral artery (MCA) is increased. This blood flow can be measured during an ultrasound.
  • No intervention is available to prevent fetal infection or damage
  • Measurement of serum IgG and IgM levels may be useful to determine those at risk or acutely infected after B19 exposure.
  • These tests should generally limited to pregnant women clearly at increased risk for acute B19 exposure during the first 18 weeks of gestation.
  • Consultation with an infectious disease physician is recommended.

More information




  • Bishara J. Freij and John L. Sever. Textbook of Neonatology. Gordon B. Avery (5th Ed). Philadelphia: Lippincott Williams & Wilkins, 1999
  • Stoll, B. J., Weiseman, L. E. Infections in perinatology. Clin. Perinatol. 24:1, 1997.
  • Brown KE, Young NS. Human parvovirus B19 infection in infants and children. Adv Pediatr Infect Dis 1998; 13:101.
  • Palasanthiran, P. (et al). Management of Perinatal Infections. Australian Society for Infectious Diseases, 2014, (p51-55).
  • Sandra K. Burchett. Manual of neonatal care. John P. Cloherty (4th Ed). Philadelphia: Lippincott-Raven, 1998.
  • Samuel P.Gotoff. Textbook of pediatrics. Behrman (16th Ed) Philadelphia: W. B. Saunders Company

Get in touch

Centre of Clinical Excellence - Women and Children
Safer Care Victoria

Version history

First published: May 2015

Last reviewed: October 2018

Review by: January 2020

Uncontrolled when downloaded

Page last updated: 17 Feb 2021

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