Maternal SARS-CoV-2 Infection, its Vertical Transmission, and Impact on Overall Perinatal Outcomes: A Narrative Review

Abstract

Background: COVID-19 pandemic caused by single-stranded RNA containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started in early December 2019 from the Wuhan city of China and has been affected millions of people, including pregnant women worldwide. Research from all over the world has shown that the SARS-CoV-2 infection can be transmitted vertically from mother to fetus but is very rare. Neonatal infection with COVID-19 accounts for only a small proportion of the total population infected. Furthermore, very few studies have observed the impact of maternal SARS-CoV-2 infection on neonatal outcomes. Thus, the literature about neonatal transmission and outcomes in COVID-19 infected antenatal women is very scattered and limited. The present review briefs on the transmission of SARS-CoV-2 infection from mother to fetus and its impact on perinatal outcomes.

Methodology: English language articles from various databases including PubMed, Scopus, EMBASE, Scholar, MedRxiv, and Web of Science and from the World Health Organization site were searched from the beginning of the COVID-19 pandemic up to June 2021. The search terms used were "SARS-CoV-2 and pregnancy outcome, "COVID-19 and neonatal outcome", "Placental changes in COVID-19 infected pregnant women", "Vertical transmission of COVID-19".

Conclusion: Maternal SARS-CoV-2 infection can be transmitted to the fetus, though uncommon, and can lead to adverse perinatal outcomes, including preterm births, intrauterine growth restriction, NICU admission, stillbirths. The data on transmission and the adverse neonatal outcome is sparse, and many more studies are needed to fully understand the mechanism by which maternal COVID-19 infection can affect fetuses and neonates.

Keywords: Coronavirus; SARS-CoV-2; neonate; placenta; pregnancy; vertical transmission.