Abstract
Background The specific impact and pathology of long COVID effects on mother and fetus post-infection have not been deeply investigated. Therefore, we explored the inflammatory response in fetal tissue from pregnant women infected at various stages.
Methods We collected villi, decidua, and placenta samples from 57 patients at Tai'an Central Hospital, who underwent either induced abortion or delivery between November 2022 and March 2023. HE staining was employed for histological examinations of these tissues. Furthermore, the concentrations of IL-6 in both umbilical cord blood and amniotic fluid were quantitatively analyzed using ELISA kits. Additionally, Western blot analysis was conducted to evaluate the expression levels of TNF-α and IL-1β in the placental tissues.
Results Among participants, 53 pregnant women were diagnosed with SARS-CoV-2 infection. No significant placental pathology differences were found between mid-term and late-term stages with the control group (P>0.05). However, Western blot analysis indicated that infected placental tissues showed higher TNF-α and IL-1β levels (P<0.05), with no notable variance in expression levels between mid-term and late-term pregnancies (P>0.05). IL-6 levels in amniotic fluid showed no significant difference, and detected no IL-6 expression in umbilical cord blood.
Conclusion Infection with SARS-CoV-2 during different periods of pregnancy can have different effects on the placenta and other tissues, emphasizing the importance of preventing and managing viral infection during pregnancy and providing clinical reference for formulating management strategies for SARS-CoV-2 infection.