SARS-CoV-2 Infection and Placental Pathology.

Placental pathophysiology in SARS-CoV-2 infection can help researchers understand more about the infection and its impact on the maternal/neonatal outcomes. This brief review provides an overview about some aspects of the placental pathology in SARS-CoV-2 infection. In total, 11 papers were included. The current literature suggests that there are no specific histopathological characteristics in the placenta related to SARS-CoV-2 infection, but placentas from infected women are more likely to show findings of maternal and/or fetal malperfusion. The most common findings in placentas from infected women were fibrin deposition and intense recruitment of inflammatory infiltrates. The transplacental transmission of this virus is unlikely to occur, probably due to low expression of the receptor for SARS-CoV-2 in placental cell types. Further studies are needed to improve our knowledge about the interaction between the virus and the mother-fetus dyad and the impact on maternal and neonatal/fetal outcomes.

A fisiopatologia da placenta na infecção por SARS-CoV-2 pode ajudar os pesquisadores a entender mais sobre a infecção e seu impacto nos resultados maternos/neonatais. Esta revisão breve fornece uma visão geral sobre alguns aspectos da patologia placentária na infecção por SARS-CoV-2. Ao todo, 11 artigos foram incluídos. A literatura atual sugere que não há características histopatológicas específicas nas placentas relacionadas à infecção por SARS-CoV-2, mas as placentas de mulheres infectadas têm maior probabilidade de apresentar achados de má perfusão materna e/ou fetal. Os achados mais comuns em placentas de mulheres infectadas foram deposição de fibrina e intenso recrutamento de infiltrado inflamatório. A transmissão transplacentária deste vírus é improvável, devido à baixa expressão do receptor para SARS-CoV-2 em tipos de células da placenta. Mais estudos são necessários para melhorar nosso conhecimento sobre a interação entre o vírus e a díade mãe-feto e o impacto nos resultados maternos e neonatais/fetais.

Is SARS-CoV-2 Vertically Transmitted?

At the end of 2019, in Wuhan (China), the onset of a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was observed. The disease, named COVID-19, has a wide spectrum of clinical presentations, ranging from asymptomatic or mild to critical, and for some patients the disease is even fatal. Apparently, being a child or being pregnant does not represent an additional risk for adverse outcomes. The purpose of this mini-review was to investigate what is in the scientific literature, so far, in regard to vertical transmission of SARS-CoV-2. Data were obtained independently by the two authors, who carried out a systematic search in the PubMed, Embase, LILACS, Cochrane, Scopus and SciELO databases using the Medical Subject Heading terms "coronavirus," "COVID-19," and "vertical transmission." Few studies about the vertical transmission of SARS-CoV-2 are found in the literature. In all case reports and case series, the mothers' infection occurred in the third trimester of pregnancy, there were no maternal deaths, and most neonates had a favorable clinical course. The virus was not detected in the neonate nasopharyngeal swab samples at birth, in the placenta, in the umbilical cord, in the amniotic fluid, in the breast milk or in the maternal vaginal swab samples in any of these articles. Only three papers reported neonatal SARS-CoV-2 infection, but there is a bias that positive pharyngeal swab samples were collected at 36 h and on the 2nd, 4th, and 17th days of life. The possibility of intrauterine infection has been based mainly on the detection of IgM and IL-6 in the neonates' serum. In conclusion, to date, no convincing evidence has been found for vertical transmission of SARS-CoV-2.