ObjectiveTo assess maternal antibody response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection during pregnancy and subsequent transplacental antibody transfer in cord blood.Study DesignThis is a prospective cohort study of Coronavirus Disease 2019 (COVID-19) polymerase chain reaction (PCR) positive pregnant women and their newborns. SARS-CoV-2 PCR (+) women were enrolled, with SARS-CoV-2 PCR (-) as control. Maternal blood was obtained at enrollment and cord blood collected at delivery. Baseline maternal and infant characteristics and neonatal outcomes were collected. Samples were analyzed using coronavirus antigen microarray containing immunologically significant antigens from SARS-CoV-2 (including nucleocapsid protein [NP], spike protein [S], S1, S2, receptor-binding domain [RBD]) which can detect SARS-CoV-2 immunoglobulin G (IgG) and immunoglobulin M (IgM).ResultsThirty-seven maternal-cord blood paired samples were analyzed for SARS-CoV-2 IgG or IgM antibodies
15 out of 20 samples from SARS-CoV-2 PCR (+) and 14 out of 17 from SARS-CoV-2 PCR (-) mothers were IgG positive. 14 out of the 17 SARS-CoV-2 PCR (-) mothers received COVID-19 vaccine during pregnancy. Difference between IgG seropositivity of naturally infected versus vaccinated mothers were significant, 75% versus 100% (