The following is a summary of “Maternal and fetal infection and antibody profiles following SARS-cov-2 infection in pregnancy: a prospective cohort study,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by chaar D, et al.
For a cohort study, researchers sought to evaluate the potential for mother-to-infant transmission of SARS-CoV-2 and patterns of antibody transfer following prenatal infection.
The study was conducted on pregnant individuals in Ontario, Canada who had COVID-19 during their pregnancy. Samples were collected at delivery, including swabs from various sites (nasopharyngeal/oropharyngeal, vaginal, anorectal), blood, breastmilk, newborn swabs (nasopharyngeal, sub-amniotic), amniotic fluid, and cord blood. SARS-CoV-2 RNA was analyzed in swabs, amniotic fluid, and breastmilk samples using qPCR. IgG assays targeting the SARS-CoV-2 spike, nucleocapsid, and receptor-binding domain proteins were used to assess blood, breastmilk, and amniotic fluid samples.
The cohort comprised 212 pregnant individuals with a history of SARS-CoV-2 infection during pregnancy between March 2020 and August 2021, along with their 214 exposed newborns. The mean age of participants was 31.0 years old (SD±5.2), and the majority delivered at term (89.6%). The infections were mostly mild (84.0%) and symptomatic (95.3%), occurring during the third trimester in most cases (77.4%), with a median of 10 weeks before delivery (IQR:15.3 weeks). At delivery, 43.3% (61/141) of participants had active SARS-CoV-2 infections, as did 14.2% (20/141) of newborns. Maternal serum (40/64), breastmilk (13/72), cord serum (147/169), and amniotic fluid (25/129) showed the presence of anti-SARS-CoV-2 IgG.
SARS-CoV-2 vertical transmission occurred at a higher rate (14.2%) than had previously been noted in the literature. In a significant number of neonates, transfer of maternal antibodies to breastfeeding, cord blood, and amniotic fluid was noted. There were ongoing analyses. The findings shed light on the conditions under which SARS-CoV-2 vertical transmission takes place and its possible effects on maternal-fetal antibody transfer.
Reference: ajog.org/article/S0002-9378(22)00991-7/fulltext
