Abnormal placental pathology and anti-SARS-CoV-2 transplacental antibody transfer following natural infection

ABSTRACT

Objective: Studies have shown that the antibodies developed in pregnant mothers who have been infected with severe acute respiratory syndrome coronavirus (SARS-COV-2) are able to cross the placenta;though, there is a decreased efficiency ratio of cord to maternal anti-receptor-binding domain IgG titers. Viral mediated placental injury may explain this finding. The objective of this study is to examine the relationship between transplacental antibody transfer and abnormal placental pathology in pregnant patients following infection with SARS-COV-2. Study Design: Pregnant patients with COVID-19 delivering at Grady Memorial Hospital were identified and enrolled into a prospective cohort study. Maternal and cord blood samples were collected at the time of delivery, and concentrations of anti- SARS-COV-2 IgG spike protein quantified using an enzyme-linked immunosorbent assay (ELISA). Placentas were sent for pathologic examination at the discretion of the obstetric provider and examined by trained pathologists for size, presence of infarcts, and other histologic findings. Results: A total of 12 women were included in the study. Demographic characteristics and clinical outcomes are reported in Table 1. There was no statistically significant difference in the mean transplacental antibody ratio for patients with and without placental infarcts, with the mean (SD) maternalcord antibody IgG ratio for patients with infarcts at 0.67 (0.47) and without was 0.73 (0.35) (p=0.81). Maternal hypertensive disorder and the presence of symptoms at time of infection were not associated with infarct in this small sample. Conclusion: Results demonstrate that in this limited sample, placental infarcts were not associated with difference in transplacental antibody transfer. Further studies are needed to understand mechanisms underlying transplacental antibody transfer. [Formula presented] [Formula presented]