COVID-19 during pregnancy should we really worry from vertical transmission or rather from fetal hypoxia and placental insufficiency? A systematic review and meta -analysis

Background: COVID-19 is the largest outbreak to strike humanity. The wide scale of fatalities and morbidities lead to a concurrent pandemic of uncertainty in scientific evidence. Conflicting evidences are released on daily basis about the neonatal outcomes of COVID-19 positive mothers. The aim of this study was to use the relevant case reports and series to determine the percentage of newborns who test positive in COVID-19 positive mothers. Secondary outcomes included examining laboratory and placental abnormalities among fetus-mother pairs. Methods: : Systematic review was performed on all studies reporting primary data on fetus-mother pairs with COVID-19. Data bases were searched for studies that met our inclusion and exclusion criteria. Results: : Final screening revealed 66 studies, from which the primary data of 1787 mother-infant pairs was obtained. Only 2.8% of mother infant pairs were tested positive, and this finding is identical to percentages reported in former coronaviridae outbreaks. Whereas, 20% manifested with intrauterine hypoxia alongside placental abnormalities suggestive of heavy placental vaso-occlusive involvement. Conclusions: : These findings suggest that while vertical transmission is unlikely, there appears to be an underlying risk of placental insufficiency due to the prothrombotic tendency observed in COVID-19 infection. Guidelines for proper prophylactic anticoagulation in COVID positive mothers need to be established.