Understanding why pregnant women are at risk of sepsis

Sara van Boeckel, Sarah Stock

Sepsis is a life-threatening condition and is the leading cause of death in mothers before and after childbirth. Our researchers are working to understand why pregnant women are more vulnerable to infections, and find ways to stop mothers dying.

Start: June 2016

End: May 2020

Why do we need this research?

Sepsis is a life-threatening condition caused by an extreme reaction by the body to an infection. Sepsis during pregnancy and shortly after birth is the leading cause of maternal death in the UK. Research has shown that pregnant women are more vulnerable to infections, and more likely to suffer severe complications, but we don’t know why.

We need to better understand how a woman’s immune system changes during pregnancy so that we can treat infections better and prevent mothers from dying.

What’s happening in this project?

Researchers funded by Tommy’s have been studying a molecule called Toll-like receptor 9 – or TLR9 for short. TLR9 sits on the surface of immune cells, and helps the immune system to recognise common infections, such as the viruses that can cause flu or herpes, or DNA from bacteria.

By studying blood samples from pregnant women in their third trimester, the team found that a certain type of immune cell has less TLR9, compared to non-pregnant women. They also found in these women that the immune system doesn’t respond in a normal way to bacterial DNA. Our researchers are currently investigating why this is the case, and why TLR9 is reduced in pregnant women.

What difference will this project make?

The results of this project suggest that the immune system is dampened during the third trimester of pregnancy. This could explain why pregnant women are more susceptible to infections and life-threatening sepsis. Ultimately, this research could lead to new ways to treat infections and sepsis in pregnant women, and help to prevent maternal death.

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