With flu season rapidly approaching, researchers from RMIT University are exploring the risks associated with pregnant women contracting the infection.
According to their work, the flu can be incredibly dangerous to pregnant women because the virus causes the immune system to go into overdrive. The team says this can lead to a number of life-threatening complications.
“We’ve known for a long time that flu can cause serious maternal and fetal complications, but how this happens has not been clearly understood,” said researcher Dr. Stella Liong. “Conventional thinking has blamed the suppressed immune system that occurs in pregnancy, but what we see is the opposite effect -- flu infection leads to a drastically heightened immune response. The inflammation we found in the circulatory system is so overwhelming, it’s like a vascular storm wreaks havoc throughout the body.”
Understanding the body’s response to infection
The researchers conducted their study on mice to determine what effect the flu can have on pregnancy. Both pregnant and non-pregnant mice were injected with the flu virus, and the researchers monitored their health outcomes.
While fetuses can’t contract the flu infection, the researchers did observe that the pregnant mice responded differently to the flu infection than the non-pregnant mice. The infection not only spread beyond the lungs in the pregnant mice, but it also led to severe inflammation in the blood vessels.
“We found a dramatic difference in these inflamed blood vessels, which can seriously affect how much blood makes it to the placenta and all the organs that support the growing baby,” said researcher Stavros Selemedis. “Our research shows the critical role that the vascular system could be playing in this, with inflammation in the blood vessels reducing blood flow and nutrient transfer from mum to baby.”
The researchers also identified a link between the flu and high blood pressure for pregnant women, as the body responded similarly in both situations. The team also noted that there were problems linked to pre-eclampsia in some subjects that may be a cause for concern.
“We found the same protein that is elevated in pre-eclampsia is also significantly elevated with the flu,” Selemedis said. “While it will take further research to unpack this link, it could mean drugs targeting vascular inflammation that are currently being tested could potentially be repurposed in the future for flu infection in pregnancy.”