Placental Injury and Antibody Transfer after Coronavirus Disease 2019 in Pregnancy

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.