Supplementary Material for: MicroRNA signatures in umbilical cord blood of neonates exposed to maternal SARS-CoV-2 infection during pregnancy

Introduction: Pregnant women are particularly susceptible to SARS-CoV-2 infection, which can provoke placental inflammation, potentially causing malperfusion and adverse pregnancy outcomes. The fetal immune system may respond to maternal infection, even without direct viral transmission. However, the molecular mechanisms driving these responses are not well understood. This study aims to examine changes in microRNA (miRNA) expression in umbilical cord blood from neonates of mothers infected with SARS-CoV-2 during pregnancy. Methods: We conducted a retrospective analysis of prospectively enrolled subjects at Innsbruck University Hospital, Austria. Umbilical cord blood was collected from 58 neonates of mothers infected with SARS-CoV-2 during pregnancy (either antepartum or peripartum) born in 2020-2023 and compared with 41 healthy controls born in 2017-2018. Total RNA was extracted, followed by miRNA next-generation sequencing and differential gene expression analysis. Ingenuity Pathway Analysis (IPA) was used to explore potential miRNA-target interactions. Results: Differential gene expression analysis identified 14 upregulated and 36 downregulated miRNAs in the cord blood of neonates from SARS-CoV-2-infected mothers compared to controls. IPA revealed enrichment in inflammatory pathways, particularly involving cytokines such as interleukin (IL)-6 and IL-10. No significant differences in miRNA expression were observed between neonates exposed antepartum versus peripartum. Discussion/Conclusion: Maternal SARS-CoV-2 infection during pregnancy is linked to altered miRNA expression in neonates' umbilical cord blood, potentially influencing inflammatory pathways. These findings shed light on the molecular mechanisms of fetal responses to maternal SARS-CoV-2 infection.