Although both scientists and parents express relief for the general protection of developing fetuses from the average viral infection, neither have understood the means of protection. While specific infections do evade this barrier and cause harm, the vast majority of viruses are stopped, and moms deliver healthy babies despite the viral infection. Researchers at Duke University report on one newly identified mechanism by which fetuses are shielded thanks to an estrogen receptor in the placenta.
As a fetus develops inside the mom’s uterus, a tiny fluctuation in development may lead to disabling or devastating consequences amplified as the baby grows. Interferon type 1, an immune system chemical messenger, can cause such issues if the mom’s infection raises inflammation inside the fetal body. As a viral infection rages in mom, her body responds with elevated interferon type I in an attempt to disable viral replication and dampen the infection. This elevation and resulting inflammation exerts profound effects on the fetus if unchecked.
The placenta, the sac of tissue and fluid in which the fetus grows, provides a physical barrier between mom’s blood supply and the baby. This wall must allow oxygen and nutrients to cross, but noxious substances like high interferon may pass through as well. In order to prevent the interferon from harming the fetus, the placenta also possesses an estrogen receptor which dampens type 1 interferon effects.
The guanine nucleotide–binding protein–coupled estrogen receptor 1 (GPER1) receives a high level of activation from the higher levels of estrogen during pregnancy. When researchers infected study animals with a virus and simultaneously blocked this receptor, the pregnant animals either had miscarriages or much smaller babies. They consider further research to define the mechanism by which the receptor triggers the protection, but this initial discovery opens a door to further understanding of how our immune systems were designed.
We can all be thankful that most viruses leave no clear harm behind for developing babies, especially the fact that practically all current research indicates pregnancies with COVID 19 do not show short nor long term harms. Besides beginning to understand how our systems protect from most viruses, we can hope to understand how certain viruses do evade the barrier and cause damage. These viruses include Zika, CMV, rubella, and a few more.
At this point, with only a glimpse into the mechanisms through which moms protect their developing babies, we in functional medicine continue to focus on optimizing a potential mom’s health before the pregnancy. Removing toxins, defeating chronic hidden infections, and lowering inflammation helps 100% of women planning a pregnancy. For those struggling with fertility and miscarriage, these steps are often necessary to even become pregnant and carry a baby to term.
This groundwork of optimal health months before conception gives the built-in systems have a better chance of protecting mom and leading to a healthier baby. Healthier more abundant lives begin before conception for both mom and infant.
Alfred T. Harding, Marisa A. Goff, Heather M. Froggatt, Jean K. Lim, Nicholas S. Heaton. GPER1 is required to protect fetal health from maternal inflammation. Science, 2021; 371 (6526): 271 DOI: 10.1126/science.aba9001
Thanks to Science Daily
Duke University. “Estrogen receptors in mom’s placenta critical during viral infection: Innate immune response would harm the fetus, so placenta tamps it down.” ScienceDaily. ScienceDaily, 21 January 2021. <www.sciencedaily.com/releases/2021/01/210121131712.htm>.