@DrEFC knew that adult males had much worse outcomes typically than females but wouldn’t have guessed it might extend to fetuses is this small data set holds true on larger testing.
New research on Covid-19 during pregnancy offers intriguing clues to one of the pandemic’s enduring mysteries: why the disease hits male adults, children, and infants harder than females.
www.statnews.com
In two studies published Tuesday in Science Translational Medicine, the Boston-based research teams found that pregnant and lactating women mount robust antibody responses to both vaccination and infection. The encouraging data also came with some twists that offer intriguing new clues to one of the pandemic’s enduring mysteries: why Covid-19 hits male adults, children, and infants harder than females.
“What’s striking here is that the mothers who are carrying male babies have much lower levels of antibodies to the coronavirus,” said
Akiko Iwasaki, a virologist and immunologist at Yale University who was not involved in the study. “What’s interesting about that is it means that the sex of the baby can dictate how the mother responds to a viral infection.”
Since the earliest days of the pandemic, epidemiological studies have pointed to
sex differences in Covid-19 patients; males get more severely ill and die more often than females. For the past year and a half, scientists like Iwasaki have been trying to tease out why that is. Last August, her team published
a study showing that men and women mount very different immune responses. Males’ defenses tend to have a slow ramp-up, but then produce more pro-inflammatory molecules, which can lead to
a dangerous over-reaction known as a “cytokine storm.”
In
one of the new studies, the Boston researchers examined maternal blood, cord blood, and the placentas from 38 pregnant Covid patients. The placenta is the life support system for a fetus, providing oxygen and nutrients; it grows from the developing embryo’s cells, not the mother’s. The researchers found that in response to Covid infection, male placentas switched on more pro-inflammatory immune activation genes than placentas supporting female fetuses.
This increased immune activation might help male fetuses stave off SARS-CoV-2, but the resulting inflammation could also pose risks, said Andrea Edlow, a maternal fetal medicine doctor at Mass General and assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School, who co-led the new studies.
“What the downstream effects are going to be for the child we still don’t know,” said Edlow. “But it’s definitely going to be important to follow up the development of these children on the basis of sex because we see these really profound changes in the placenta that suggest that the intrauterine environment is suddenly altered even in the setting of mild maternal disease.”
What seems more clear, and surprising, is how those changes feed back into what the mother’s immune system is doing. Covid-infected patients produced fewer antibodies if their fetus was male. And they also transferred far fewer of these protective antibodies to the developing male babies.
