Discussion
Physiological adaptive changes, increased oxygen consumption, and suppressed immune state increase the susceptibility of pregnant women to respiratory pathogens and pneumonia1. Previous reports have shown that HPV, HIV, and other viruses are related to increased rate of preterm birth2,3. However, whether preterm delivery described in this report was caused by SARS-CoV-2 remains unknown. The case in the present report is a pregnant woman infected with COVID-19 that rapidly developed into severe respiratory infection following vaginal delivery. Since there is only one case in the present report, it is difficult to draw conclusions with regard to the etiology of the symptoms after vaginal delivery. Whether the strong contractions during natural delivery can exacerbate pneumonia associated with COVID-19 still needs to be confirmed. Huijun et. al. have reported that none of nine confirmed patients infected with SARS-CoV-2 developed severe COVID-19 pneumonia or died after the caesarean section in their third trimester4, suggesting that cesarean section may carry less risk in pregnant women infected with SARS-CoV-2. Due to the increased oxygen consumption and pulmonary load during pregnancy, cesarean section may help to avoid adverse clinical consequences caused by pulmonary insufficiency and also reduces the possibility of maternal viremia during delivery. In addition, we didn’t observe any abnormalities from the newborn baby, which indicated no mother-to-child transmission by vaginal delivery. This observation was consistent with Huijun and colleagues’ finding of no intrauterine transmission of COVID-19.