Pregnant women pass fewer coronavirus antibodies to unborn boys than girls: Study

During the COVID-19 pandemic, medics had found that there has been a higher prevalence and increased severity of the coronavirus disease in males as compared to females. Now, in a new study published in Science Transitional Medicine journal on October 23, scientists have found the underlying mechanisms accounting for this difference in contraction, onset, and severity of the coronavirus based on sex difference.

Boston-based researchers suggest that the COVID-19 disease’s difference may be linked to the innate differences in immune responses in both sexes as the ‘placental antiviral response’ plays a key role with respect to the implications of the COVID-19 disease in adults. 

Pregnant women transfer 'fewer coronavirus antibodies' to unborn males

Scientists, who studied medical data of 38 women infected with the coronavirus during pregnancy found that they transferred fewer antibodies to the male unborn as compared to the females. At least half of the pregnant women that were carrying a male child were found to have fewer antibodies than those pregnant with a female child.

Scientists also found that the women with baby boys passed fewer coronavirus antibodies to male fetuses than the females. The team estimated the maternal-fetal antibody transfer, and the viral-induced placental interferon responses, as well as the fetal sex in pregnant women. They measured the level of antibodies among the expectant mothers by taking blood samples and calculated fetuses' antibody levels using placenta tissue as well as blood samples from the umbilical cords. 

“Mortality and morbidity risk during the perinatal period and infancy is higher in males than females,” the study claimed, adding that the underlying COVID-19 susceptibility of males is related to “evolutionary differences that occur throughout pregnancy and in the perinatal period.”

The scientists, however, argued that the precise mechanism that leads to this differential female survival benefit is not completely understood. 

The study confirmed that the male vulnerability for contraction of the novel coronavirus, in general, in both male infants and adults fare worse in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There are higher rates of severe COVID-19 disease in infants associated with the multisystem inflammatory syndrome (MIS-C), the study found. Scientists stated that the data confirms the vulnerability of the male immune system to SARS-CoV-2 in pediatric populations.