Contributor: Sharon Keiser, MD, Maternal-Fetal Medicine
Last Update 7/2017
Human parvovirus B19 is the most commonly reported infectious cause of fetal anemia. This is a small, non-enveloped single-stranded DNA virus, and is the only parvovirus known to cause disease in humans. It preferentially infects rapidly dividing cells and is cytotoxic to erythroid progenitor cells. In addition, it may stimulate a cellular process initiating apoptosis.
B19 viremia begins approximately 6 days after exposure and lasts for one week in immunocompetent individuals. It can be detected in blood and secretions 5-10 days after exposure.
Reticular rash on trunk
Transient aplastic crisis (in patients with underlying hemoglobinopathy)
Fetal Hydrops (up to 8 weeks after maternal infection)
Spontaneous abortion (1-11 weeks after maternal infection)
Infected person is infectious 5-10 days after exposure (before onset of symptoms)
Risk of Transmission:
Exposure to an infected household member – 50% risk of seroconversion
Exposure in a childcare setting/classroom – 20-50% risk of seroconversion
Transmission to Fetus
Highest risk is when transmission occurs prior to 22 weeks EGA
J Prenat Med. 2010 Oct-Dec; 4(4):63-66
ACOG Practice Bulletin #151https://www.mombaby.org/ob-algorighms?#medical-complications-infections
Clin Lab Med. 2016 Jun;36(2):407-19
UNC Center for Maternal and Infant Health OB Algorithms (https://www.mombaby.org/ob-algorighms?#medical-complications-infections.