Assessing maternal and fetal SARS-CoV-2 viral load, antibody profiles and placental pathology following prenatal infection

Evaluate mother-to-infant transmission potential of SARS-CoV-2 and patterns antibody transfer following prenatal infection. Prospective cohort pregnant individuals infected with COVID-19. Samples collected at delivery included maternal swabs (nasopharyngeal/oropharyngeal, vaginal, anorectal), blood, breastmilk, newborn (nasopharyngeal, sub-amniotic), amniotic fluid, cord placenta. were analyzed by qPCR for SARS-CoV-2-RNA IgG assays targeting the spike (S), nucleocapsid (N), receptor binding domain (RBD) proteins. Placentas evaluated histologic lesions. The 213 who delivered between from March 2020 to August 2021, their 215 exposed offspring. was evident in nasopharyngeal (64/145), vaginal (3/184) anorectal (5/182) breastmilk (1/38). A total 27/212 infants (12.7%) demonstrated evidence mother-to-child SARS-CoV-2; detected (21/142), fluid (3/77), sub-amniotic (1/165), placenta homogenates (6/138). Anti-SARS-CoV-2 IgA IgM 1/189 neonates. Maternal serum anti-RBD, anti-N anti-S significantly positively correlated ( R =0.26, 0.24, 0.23, respectively; P <0.05). Antibody ratio anti-RBD weeks since infection during pregnancy (R = 0.28, 6/138 placentas; placentas characterized acute (33/113), chronic inflammation (20/113), (39/113) fetal (12/113) vascular malperfusion. rate vertical antibodies tissues high. There no pathological differences controls. Further investigation into timing is warranted its implications on offspring outcomes.