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… Show more
“…Of these, Placental Endonuclease, Poly(U) Specific (ENDOU, placental protein 11 or PP11), which has high homology with the coronavirus endoribonuclease Nsp15 [ 13 ] ( Fig. 1 C), and Human Angiotensin-Converting Enzyme 2 (ACE2), the cellular entry receptor for SARS-CoV-2 [ 14 , 15 ] were specifically selected for validation by RT-PCR and IHC. Additionally, placental RNAseq transcript abundance mapped to ENDOU’s PPI network suggests putative interactions of ENDOU ( Fig.…”
“…Of these, Placental Endonuclease, Poly(U) Specific (ENDOU, placental protein 11 or PP11), which has high homology with the coronavirus endoribonuclease Nsp15 [ 13 ] ( Fig. 1 C), and Human Angiotensin-Converting Enzyme 2 (ACE2), the cellular entry receptor for SARS-CoV-2 [ 14 , 15 ] were specifically selected for validation by RT-PCR and IHC. Additionally, placental RNAseq transcript abundance mapped to ENDOU’s PPI network suggests putative interactions of ENDOU ( Fig.…”
“…To date, it remains unclear if vertical transmission—either intrauterine, intrapartum, or immediately postpartum—of SARS-CoV-2 occurs. 13 , 14 , 15 , 16 , 17 Further evidence concluding whether SARS-CoV-2 can infect the placenta, traverse the placental barrier or induce morphologic changes is needed. Reports have suggested that cell entry of SARS-CoV-2 is mediated through the angiotensin-converting enzyme 2 (ACE2) receptor.…”
Section: Discussionmentioning
confidence: 99%
“…11 , 12 Evidence regarding the occurrence of antepartum or peripartum vertical transmission has been conflicting to date. 13 , 14 , 15 , 16 , 17 AJOG MFM at a Glance
Why was this study conducted?
The association between maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and placental histopathology is not well known.…”
Background
The impact of maternal severe acute respiratory syndrome coronavirus 2 infection on placental histopathology is not well known.
Objective
To determine if any significant placental histopathologic changes occur after the diagnosis of severe acute respiratory syndrome coronavirus 2 infection during pregnancy and whether these changes are correlated with the presence or absence of symptoms associated with the infection.
Study Design
A retrospective cohort study of women diagnosed as having severe acute respiratory syndrome coronavirus 2 infection who delivered at a single center from April 9, 2020 to April 27, 2020, and had placental specimens reviewed by the Department of Pathology. Women with singleton gestations and laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection were eligible for inclusion. Historical controls selected from a cohort of women who delivered 6 months before the study period were matched in a 1:1 fashion by weeks of gestation at delivery. Histopathologic characteristics were evaluated in each placenta, and the incidence of these findings was compared between placentas of those who received a diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection and historical controls, and between placentas from patients with or without typical symptoms related to the infection. Statistical analyses included the use of Wilcoxon rank-sum test and Fisher’s exact test for the comparison of categorical and continuous variables. Statistical significance was defined as a
P
value of <.05.
Results
A total of 50 placentas after the diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection and 50 historical controls were analyzed. Among the placentas from patients diagnosed with severe acute respiratory syndrome coronavirus 2 infection, 3 (6%) were preterm (33 3/7, 34 6/7, and 36 6/7 weeks of gestation), 16 (32%) were from patients with typical symptoms related to the infection, and 34 (68%) were from patients without typical symptoms related to the infection. All patients had received a diagnosis of severe acute respiratory syndrome coronavirus 2 infection in the third trimester. Decidual vasculopathy was not visualized in any of the placentas from patients diagnosed as having severe acute respiratory syndrome coronavirus 2 infection. There was no statistically significant difference in placental histopathologic characteristics between the groups. Severe acute respiratory syndrome coronavirus 2 test results for all neonates at 24 hours of life were negative.
Conclusion
Based on the results of this study, there are no significant placental histopathologic changes that occur after the diagnosis of severe acute respiratory syndrome coronavirus 2 infection in women during the third trimester of pregnancy compared with a gestational age–matched historical control group. Similar incide...
“…Lamouroux et al 26 and Mahyuddin et al 27 , mention that many microorganisms are able to violate the maternal immune system barrier through the placenta and result in severe fetal consequences. Viruses can exert dynamic fluctuations in the immune environment of the placenta throughout pregnancy and contribute to changes in fetal susceptibility 27 .…”
SUMMARY OBJECTIVE To review the current scientific evidence of vertical transmission related to coronavirus disease 2019 (COVID-19). METHODS An integrative review was performed by two independent researchers, based on the literature available in the MEDLINE (via PubMed) and LILACS databases, using the descriptors “pregnancy” AND “COVID-19” AND “vertical transmission”. This search included case reports or case series published up until 17th June 2020 in English or Portuguese. After reading the articles available in their entirety, those related specifically to the potential risks of vertical transmission of COVID-19 during pregnancy were selected. We initially found a total of 57 articles; 26 were carefully screened and 15 were finally selected. RESULTS Pregnancy can make women more susceptible to infections, especially by viral pathogens, given the various physiological and immunological changes that occur to maintain maternal-fetal balance. It is speculated that the fetus may be a possible target for COVID-19. Few studies (3 out of 15) in our analysis have found positive results for SARS-CoV-2 in fetal membranes, placenta, and in newborns right after birth. Additionally, no difference was noticed when comparing different modes of delivery, and seems reasonable to assume that pregnant women with stable clinical conditions can be encouraged for vaginal delivery. CONCLUSION Further studies with a great number of cases are warranted to elucidate whether the virus may be vertically transmitted to the fetus and if any maternal conditions can influence that. Our findings seem to demonstrate that vertical transmission is possible but quite unusual.
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