By learning more about the immune system changes that occur during pregnancy, scientists hope they can someday predict if babies will be born prematurely.
“Pregnancy is a unique immunological state. We found that the timing of immune system changes follows a precise and predictable pattern in normal pregnancy,” said study senior author Dr. Brice Gaudilliere. He’s an assistant professor of anesthesiology, perioperative and pain medicine at Stanford University School of Medicine in California.
If scientists can identify immune-system changes predicting premature birth, they say they might eventually develop a blood test to detect it.
“Ultimately, we want to be able to ask, ‘Does your immune clock of pregnancy run too slow or too fast?'” Gaudilliere said in a university news release.
Nearly 10 percent of U.S. infants are born three or more weeks early. Currently, doctors have no reliable way to predict which babies will be born prematurely.
For the study, the researchers collected blood samples from 18 women who had full-term pregnancies. The women gave one sample during each trimester and another six weeks after childbirth. The researchers used samples from another group of 10 women who also had full-term pregnancies to verify the findings.
Using a technique called mass cytometry, the researchers simultaneously measured up to 50 properties of each immune cell in the blood samples. The investigators counted the types of immune cells, determined which signaling pathways were most active in each cell, and assessed how the cells reacted when exposed to compounds that mimic bacterial or viral infection.
The research team then used advanced statistical modeling to document the immune system changes occurring throughout pregnancy. (These adjustments keep the mother’s body from rejecting the unborn baby.)
“This algorithm is telling us how specific immune cell types are experiencing pregnancy,” Gaudilliere said.
The study confirmed that natural killer cells and certain white blood cells have enhanced action during pregnancy. The researchers also found that a signaling pathway among helper T-cells increases on a precise schedule.
“It’s really exciting that an immunological clock of pregnancy exists,” said study lead author Nima Aghaeepour, an instructor in anesthesiology, perioperative and pain medicine.
“Now that we have a reference for normal development of the immune system throughout pregnancy, we can use that as a baseline for future studies to understand when someone’s immune system is not adapting to pregnancy the way we would expect,” Aghaeepour added.
The study results were published Sept. 1 in Science Immunology.
The U.S. National Library of Medicine has more on preterm birth.