Clinical features and the maternal and neonatal outcomes of pregnant women with coronavirus disease 2019

Rui Nie; Shao-shuai Wang; Qiong Yang; Cui-fang Fan; Yu-ling Liu; Wen-cong He; Mei Jiang; Cheng-cheng Liu; Wan-jiang Zeng; Jian-li Wu; Kutluk Oktay; Ling Feng; Lei Jin

However, this newborn's case may also be real vertical transmission of SARS-CoV-2 since the mother wore N95 masks during the cesarean section, and all medical staff wore protective suits. Furthermore, the newborn was isolated immediately after birth. These preventive measures should have decreased the risk of SARS-CoV-2 transmission through the respiratory system of the mother, medical staff, and hospital environment. Second, previous studies have shown that ACE2 is expressed by the human endometrium and placenta 19, 20 . A recent study revealed that ACE2 is highly expressed in maternal-fetal interface cells, including stromal cells and perivascular cells of decidua, and cytotrophoblast and syncytiotrophoblast in placenta 21 . Thus, SARS-CoV-2 may also be attracted to the human endometrium and placenta though ACE2, causing vertical transmission of SARS-CoV-2. Also, the SARS-CoV-2 has been detected in urine and stool 22 , suggesting a possibility of ascending infection of the uterus, placenta, and fetus. Third, it has been reported that the ACE2-expressing cell ratio is variable between individuals, which may explain why some people are more vulnerable to SARS-CoV-2 14 . This characteristic of ACE2 may explain why SARS-CoV-2 infected only one out of 26 newborns.