Abstract
Background We examined the relationship between placental histopathology and transplacental antibody transfer in pregnant patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods Differences in plasma concentrations of anti-receptor biding domain (RBD) immunoglobulin (Ig)G antibodies in maternal and cord blood were analyzed according to presence of placental injury. Results Median anti-RBD IgG concentrations in cord blood with placental injury (n = 7) did not differ significantly from those without injury (n = 16) (median 2.7 [interquartile range {IQR}, 1.8-3.6] vs 2.7 [IQR, 2.4-2.9], P = 0.59). However, they were associated with lower transfer ratios (median 0.77 [IQR, 0.61-0.97] vs 0.97 [IQR, 0.80-1.01], P = 0.05). Conclusions SARS-CoV-2 placental injury may mediate reduced maternal-fetal antibody transfer.