Abstract
Parvovirus B19 (PVB19) is a widespread infection that may affects 1- 5% of pregnant women; in epidemics, the rate of infection is even higher. In spite of 30%- 50% vertical transmission to the fetus, pregnancy outcome is generally unaffected. Diagnosis of infection is by maternal serology and/or PCR, but fetal infection is diagnosed by PCR from amniotic fluid or, if fetal cordocentesis is carried out, from fetal blood. Reports on major congenital anomalies among offspring of mothers infected by Parvovirus B19 affecting different organs are scanty, as the virus does not seem to be a significant human teratogen. However, especially if infection occurs in the first half of pregnancy, it may cause significant fetal damage and rarely also brain anomalies and neurodevelopmental problems. PVB19 is an important cause of fetal loss throughout gestation, especially in the second half of pregnancy; at that time spontaneous fetal loss from other causes is relatively rare. The virus infects fetal erythroid progenitor cells causing apoptosis and, as a result of shortened half-life of erythrocytes moderate to severe fetal anemia. Severe thrombocytopenia is also common. According to its severity, the anemia may lead to high output cardiac failure and therefore non immune hydrops fetalis (NIHF). PVB19 may also directly infect myocardial cells and produce myocarditis that aggravates the cardiac failure. Intrauterine fetal transfusion, which is commonly carried out for the treatment of severe fetal anemia, significantly reduces fetal morbidity. There are little data regarding the long-term neurodevelopmental outcome in infected children. Although data are inadequate, 10-15% of the children infected with PVB19 having hydrops fetalis will suffer from neurodevelopmental impairment. However, there seem to be no data on infected fetuses without hydrops. It is also unknown whether neurodevelopmental sequelae result from the anemia or from the complications of the intrauterine transfusion, since children who had fetal hydrops and intrauterine transfusion due to other etiologies were also found to have a high rate of neurodevelopmental problems. Since PVB19 infection can cause severe morbidity and mortality, it should be part of the routine work up of complicated pregnancies, especially when fetal hydrops is suspected. Risk assessment for maternal infection during pregnancy is particularly important during epidemics when sero-conversion rates are high. Until today, there is no effective immunization against parvovirus.
Original language | English |
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Title of host publication | Advances in Health and Disease |
Publisher | Nova Science Publishers, Inc. |
Pages | 33-68 |
Number of pages | 36 |
Volume | 4 |
ISBN (Electronic) | 9781536133462 |
ISBN (Print) | 9781536133455 |
State | Published - 1 Jan 2018 |
Externally published | Yes |
Keywords
- Anemia
- Malformations
- Neurodevelopmental impairment
- Non-immune fetal hydrops
- Parvovirus B19
- Pregnancy