Cohort 2: RT PCR testing
Of 608 asymptomatic women who had a nasopharyngeal swab, SARS-CoV-2 RNA was detected in one woman, suggesting a prevalence of asymptomatic infection of 0·16% (1/608, 95%CI 0%-0·9%). Serology demonstrated positive for IgG SARS-CoV-2 antibodies but was negative for IgM antibodies. SARS-CoV-2 RNA was not detected in a nasopharyngeal swab from her baby. The umbilical cord blood, however, was positive for the presence of IgG anti-SARS-CoV-2 antibodies.