SARS-CoV-2 Antibody Response among Women Infected during Pregnancy

Objectives: Novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) virus has been declared a pandemic by the World Health Organization as of March 11, 2020. Pregnant women naturally have a reduced immune system due to immunological changes and decreased lung capacity due to respiratory adaptations, making them more susceptible to coronavirus complications. Within the Mount Sinai Health system, more than 15,000 deliveries are performed annually. We began to care for pregnant women with known COVID-19 infections in late March of 2020. In early April 2020, a policy was implemented to perform universal COVID-19 testing for all women planning to deliver within the Mount Sinai Health system. We examined the antibody response of postpartum women who delivered at Mount Sinai Hospital with a SARS-CoV-2 infection between the study intervals during March 15, 2020, through April 30, 2020.

Study design: This was a prospective observational study examining the immune response of pregnant women who delivered at Mount Sinai Hospital with a polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection. Women with a SARS-CoV-2 infection were contacted via phone to discuss participation in the study. Patients who consented were scheduled for a phlebotomy visit to assess their antibody titer levels to COVID-19. The COVID-19 enzyme-linked immunosorbent assay (ELISA) immunoglobulin (Ig)-G antibody test was used to evaluate the patients' antibody titers. The assay detects IgG antibodies for the detection of IgG seroconversion in patients following a known recent SARS-CoV-2 infection.

Results: A total of 120 patients were identified with a documented SARS-CoV-2 infection who delivered within the prespecified time frame. Of those patients, 25 women agreed to participate and were included. Of them, 64.00% were Caucasian with a mean age of 35 years. The mean body mass index (BMI) was 30 kg/m² and the majority of patients had commercial insurance (88.00%). The majority of women were asymptomatic for COVID-19 at the time of admission (80.00%) and the average gestational age of delivery and diagnosis of COVID-19 was 39 weeks' gestation. The later the gestational age at the time of diagnosis, the lower the antibody titer response. When examining the interval from diagnosis to antibody titer analysis, patients with the highest titers (2,880) tended to have a shorter interval between their COVID-19 diagnosis and the time at which the titer level was drawn. Patients with symptoms on admission had similar antibody titer levels when compared with women who were asymptomatic.

Conclusion: The antibody response among women infected with COVID-19 during pregnancy appears to be greater when the patients are diagnosed at an earlier gestational age.

Key points: · COVID-19 antibody status appears to be greater when diagnosed at an earlier gestational age.. · Asymptomatic and symptomatic pregnant women had similar antibody responses.. · Patients with the highest titers tended to have a shorter interval between their COVID-19 diagnoses..