While initially recognized as causing respiratory disease, the SARS-CoV-2 virus also affects many other organs leading to other complications. It has emerged that advanced age and obesity are risk factors for complications but questions concerning the potential effects on fetal health and successful pregnancy for those infected with SARS-CoV-2 remain largely unanswered. Here, we examine human pre-gastrulation embryos to determine the expression patterns of the genes ACE2, encoding the SARS-CoV-2 receptor, and TMPRSS2, encoding a protease that cleaves both the viral spike protein and the ACE2 receptor to facilitate infection. We show expression and co-expression of these genes in the trophoblast of the blastocyst and syncytiotrophoblast and hypoblast of the implantation stages, which develop into tissues that interact with the maternal blood supply for nutrient exchange. Expression of ACE2 and TMPRSS2 in these tissues raises the possibility for vertical transmission and indicates that further work is required to understand potential risks to implantation, placental health and fetal health that require further study.

虽然 SARS-CoV-2 病毒最初被认为会引起呼吸道疾病，但它也会影响许多其他器官，导致其他并发症。研究表明，高龄和肥胖是并发症的危险因素，但有关 SARS-CoV-2 感染者对胎儿健康和成功妊娠的潜在影响的问题在很大程度上仍未得到解答。在这里，我们检查人类原肠胚形成前胚胎，以确定编码 SARS-CoV-2 受体的基因ACE2和编码蛋白酶的TMPRSS2基因的表达模式，该蛋白酶可裂解病毒刺突蛋白和 ACE2 受体以促进感染。我们展示了这些基因在囊胚滋养层、合体滋养层和着床阶段下胚层中的表达和共表达，这些滋养层发育成与母体血液供应相互作用进行营养交换的组织。这些组织中ACE2和TMPRSS2的表达增加了垂直传播的可能性，并表明需要进一步开展工作来了解植入、胎盘健康和胎儿健康的潜在风险，需要进一步研究。