The Association of COVID-19 Infection in Pregnancy and Vertical Transmission: Literature Review

Coronavirus disease 2019 (COVID-19) is caused by a new beta coronavirus (severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2) and has resulted in a worldwide pandemic. Although previous research on other beta coronaviruses has found detrimental effects on pregnant women and neonates, it is uncertain whether vertical transmission of SARS-CoV-2 exists. We conducted a literature review to explore the association between confirmed COVID-19 infection during the pregnancy and potential vertical transmission of the virus. We searched PubMed using the following medical subject headings (MeSH): ("Coronavirus"[MeSH]) AND "Pregnancy"[MeSH]; ("Coronavirus"[MeSH]) AND "Infectious Disease Transmission, Vertical"[MeSH]. Inclusion criteria were full articles, female study objects, English language, papers published within one year, and human studies. Non-English papers, animal studies, meta-analysis, clinical trials, literature reviews, and systematic reviews were excluded from our data collection. Sixteen articles were eventually selected for this review. By July 2020, two cases have demonstrated high chances of vertical transmission, but definitive evidence is lacking; these women were nearly all infected in the second or third trimester, and most underwent cesarean delivery. The virus's effects earlier in pregnancy are mainly unknown; no neonates have been delivered from women infected in the first trimester of pregnancy. More research and data are needed to assess the presence and potential consequence of vertical transmission of SARS-CoV-2. The preferred approach to investigating a possible intrauterine viral infection is to detect the virus in the placenta, amniotic fluid, cord blood, or neonatal pharyngeal swab samples collected immediately after birth.