Mechanisms and evidence of vertical transmission of infections in pregnancy including SARS-CoV-2s.
Prenat Diagn
; 40(13): 1655-1670, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-32529643
ABSTRACT
There remain unanswered questions concerning mother-to-child-transmission of SARS-CoV-2. Despite reports of neonatal COVID-19, SARS-CoV-2 has not been consistently isolated in perinatal samples, thus definitive proof of transplacental infection is still lacking. To address these questions, we assessed investigative tools used to confirm maternal-fetal infection and known protective mechanisms of the placental barrier that prevent transplacental pathogen migration. Forty studies of COVID-19 pregnancies reviewed suggest a lack of consensus on diagnostic strategy for congenital infection. Although real-time polymerase chain reaction of neonatal swabs was universally performed, a wide range of clinical samples was screened including vaginal secretions (22.5%), amniotic fluid (35%), breast milk (22.5%) and umbilical cord blood. Neonatal COVID-19 was reported in eight studies, two of which were based on the detection of SARS-CoV-2 IgM in neonatal blood. Histological examination demonstrated sparse viral particles, vascular malperfusion and inflammation in the placenta from pregnant women with COVID-19. The paucity of placental co-expression of ACE-2 and TMPRSS2, two receptors involved in cytoplasmic entry of SARS-CoV-2, may explain its relative insensitivity to transplacental infection. Viral interactions may utilise membrane receptors other than ACE-2 thus, tissue susceptibility may be broader than currently known. Further spatial-temporal studies are needed to determine the true potential for transplacental migration.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Complicações Infecciosas na Gravidez
/
Transmissão Vertical de Doenças Infecciosas
/
COVID-19
Limite:
Female
/
Humans
/
Pregnancy
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article