Introduction
Coronavirus disease 2019 (COVID-19) has emerged worldwide while a subset of people was infected severely, the others recovered from the disease without symptoms. COVID-19 has been shown to have potential adverse effects on pregnancy and neonatal outcomes. Pregnancy itself is a risk factor for the severity of COVID-19 disease, with an increased risk of ICU admission, maternal morbidity, and mortality1,2. Furthermore, pregnancy complications such as preeclampsia and preterm birth are more likely to occur in women diagnosed with COVID-19 3,4.
The predominance of Lactobacillus species (spp.) plays a key role in the inhibition of binding non-domestic and potentially harmful microorganisms to epithelial cells 5–7.Lactobacillus maintains the protective low vaginal pH through secreting of lactic acid 8. Pregnant women with decreased amounts of Lactobacillus crispatus, Lactobacillus gasseri, and Lactobacillus jensenii in the vaginal microbiota are more likely to deliver preterm 9. Likewise, the abundance of Gardnerella vaginalis increases the risk of preterm birth (PTB) 5,10.
The mechanism of action of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) on pregnancy varies and remains unknown. The SARS-CoV-2 genome has been identified in the vaginal mucosa of a pregnant woman 11. Indeed, the role of SARS-CoV-2 infection in vaginal microbiome composition in pregnant women with COVID-19 has not yet been investigated. Therefore, we anticipate that COVID-19 may unfavorably affect the composition of the vaginal microbiota, resulting in adverse pregnancy outcomes. We aimed to describe the alterations of the composition of vaginal microbiota in pregnant women with COVID-19.