Pregnant women pass along protective COVID antibodies to their babies
New research has found that the protective antibodies pregnant women make against COVID-19 are often passed on to their foetuses – conveying natural immunity, amongst other benefits. Researchers at Weill Cornell Medicine also suggest that vaccinating mothers-to-be may also have benefits for their newborns.
According to Dr. Yawei Jenny Yang, an assistant professor of pathology and laboratory medicine at Weill Cornell Medicine,blood samples from 88 women who gave birth at New York-Presbyterian/Weill Cornell Medical Center between March and May 2020 had traces of COVID-19 antibodies. This indicated all the women had contracted the virus at some point, even though 58% of those women had no symptoms.
Furthermore, while antibodies were detected in both symptomatic and asymptomatic women, the researchers observed that the concentration of antibodies was significantly higher in symptomatic women. They also found that the general pattern of antibody response in pregnant women was similar to the response seen in the larger patient population in other patients.
In addition, 78% of the babies born to these women had detectable antibodies in their umbilical cord blood. There was no evidence that any of the infants had been directly infected with the virus and all were COVID negative at the time of birth, further indicating that the antibodies had crossed the placenta — the organ that provides oxygen and nutrients to a growing baby during pregnancy — into the foetal bloodstream. Newborns with symptomatic mothers also had higher antibody levels than those whose mothers had no COVID symptoms.
This implies that pregnant women could pass along vaccine-generated antibodies in the same way, potentially shielding both mother and child from future infection.
Dr. Laura Riley, chair of the Department of Obstetrics and Gynecology at Weill Cornell Medicine, obstetrician and gynecologist-in-chief at New York-Presbyterian/Weill Cornell and one of the study’s co-authors, is still advising pregnant patients who decide to get vaccinated to continue to follow current safety guidelines to prevent the spread of the disease.
Dr. Riley, Dr. Yang and their colleagues are currently enrolling pregnant women who receive the vaccine, as well as vaccinated mothers who are breastfeeding, to assess the antibody response in those groups after vaccination, to help guide maternal vaccination strategies moving forward.
