A recent study has found that pregnancy is a challenge for the mother’s immune system from the outset as half of the genes in the foetus are foreign to her body.
The immune system has to strike a balance between tolerating the foetus and protecting the mother and foetus from infections. Throughout the pregnancy, an immunological balance takes place between mother and child. At the Norwegian University of Science and Technology’s (NTNU) Centre for Molecular Inflammation Research (CEMIR), a research group is engaged in studying inflammation in pregnancy. The group has made findings that shed light on how the immune system behaves during pregnancy.
Anders Hagen Jarmund, a research programme student, and his colleagues at CEMIR are the first researchers to survey the development of women’s immune responses throughout pregnancy.
The study followed 707 women with normal pregnancies, who gave birth to healthy full-term and post-term babies.
“Our immune system is regulated by cell signalling molecules called cytokines. The signalling molecules can trigger or stop immune responses. We profiled a number of different cytokines in the blood using a simple blood sample from the mother. Linking the measurements of lots of cytokines at several points in the pregnancy gave us an imprint of the mother’s immune response,” says Jarmund.
“Because we have so many healthy pregnant women in the study, we were able to find the ‘standard’ for how the immune system behaves during normal pregnancies,” he says.
Blood samples from the mother provide detailed information about inflammatory conditions in the body, the strain on the foetus and early signs of the immunological disorder.
The researchers found that immune activity in normal pregnancies follows a certain pattern, with elevated immune activation in the first three months, then a calmer phase the next three and higher activity in the last three months, especially when childbirth is imminent
Jarmund believes that studying the immune system’s behaviour in normal pregnancies can be very useful.
“Our study can serve as a reference for what’s normal at different stages throughout pregnancy. By comparing analyses of blood samples from the pregnant woman with our survey, we can detect abnormalities very early,” Jarmund said.
“Early detection can help the doctor assess whether the woman has an increased risk of developing a disease and needs extra close follow-up.”
Jarmund discovered several conditions in the mother or foetus that created abnormalities in the immune response. “The immune changes detected with cytokine profiling are so sensitive that they capture the effects of obesity and smoking in the mother. The immune system is also affected if the foetus is stunted, and may even indicate whether it’s a boy or a girl,” says Jarmund.