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.