Outcome of fetuses with congenital parvovirus B19 infection: systematic review and meta-analysis

OBJECTIVE: To explore the outcome of fetuses affected by congenital Parvovirus B19 (PB19) Infection. METHODS: The outcomes observed were: miscarriage, perinatal death (PND), intra-uterine death (IUD), neonatal death (NND), spontaneous resolution of hydrops or fetal anemia, intra-uterine transfusion (IUT), resolution of hydrops or anemia after transfusion, fetal loss following transfusion, abnormal brain scan after birth, abnormal neurodevelopmental outcome. All the observed outcomes were reported in fetuses presenting and in those not presenting signs of hydrops on ultrasound. A sub-group analysis was performed including hydropic and non-hydropic fetuses < and ≥ 20 weeks of gestation respectively. Meta-analyses of proportions and meta-analyses using individual data random-effect logistic regression were used to analyze the data. RESULTS: Thirty-seven observational studies (654 fetuses affected by PB19 infection) were included. The risk of miscarriage (OR: 11.5, 95% CI 2.7-49.7) and PND (OR: 4.2, 95% CI 1.6-11.0) was higher in fetuses affected by PB19 infection presenting compared to those not presenting with hydrops on ultrasound. In fetuses affected by hydrops, spontaneous resolution of the infection, defined as disappearance of hydrops without the need for IUT, occurred in 5.2% (95% CI 2.5-8.8) of cases, while in the group of fetuses not affected by hydrops, resolution occurred in 49.6% (95% CI 20.7-78.6) of cases. IUT was performed in 78.7% (95% CI 66.4-88.8) of hydropic and in 29.6% (95% CI 6.0-61.6) of non-hydropic fetuses affected by congenital PB19 infection and resolution of the infection after IUT occurred in 55.1% (95% CI 34.0-75.3) of fetuses presenting and in 100% (95% CI 57.3-100) of cases not presenting signs of hydrops on ultrasound. The risk of fetal loss after IUT was higher in fetuses affected compared to those not affected by hydrops (OR: 9.8 (95% CI 2.8-34.6). Assessment of neurodevelopmental outcome was affected by the very small number of included cases, thereby precluding the achievement of adequate statistical power. The prevalence of abnormal brain imaging was 9.8% (95% CI 2.5-21.0) in fetuses affected and 0.0% (95% CI 0.0-7.0) in those not affected by hydrops, while the corresponding figures for abnormal neurodevelopmental outcome was 9.5% (95% CI2.6-20.2) and 0.0% (95% 0.0-0.8). CONCLUSION: Hydrops is the main determinant of mortality and adverse perinatal outcome in fetuses affected by PB19 infection. Perinatal outcome in non-hydropic fetuses is generally favorable