Pregnancy 'immune clock' find can help doctors predict preterm births

Good news for moms-to-be, as doctors may now be able to predict premature births after a research recently found that women have an 'immune clock' during pregnancy.

According to researchers from Stanford University's school of medicine, the changes in immune system are precisely timed and can help establish when the body is not adapting as expected.

Using a combination of mass cytometry - a technique developed to simultaneously measure up to 50 properties of each immune cell in the blood samples - and computational modeling, the researchers have described a 'clock' for the immunological events leading up to birth.

The findings revealed that there is an immune clock of pregnancy and it may help doctors predict preterm birth.

"Pregnancy is a unique immunological state and we found that the timing of immune system changes and follows a precise and predictable pattern in normal pregnancy," said senior author Brice Gaudilliere.

The new research aims to understand why preterm births happen and how it could be prevented.

"It's really exciting that an immunological clock of pregnancy exists," said lead author Nima Aghaeepour.

"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.

If scientists identify an immune signature of impending preterm birth, they should be able to design a blood test to detect it.

The team collected blood samples from 18 women who had full-term pregnancies.

Each woman gave four blood samples, one during each of the three trimesters of pregnancy and one six weeks after delivery. Samples from an additional group of 10 women with full-term pregnancies were used to validate the findings.

The researchers used mass cytometry, a technique developed at Stanford, to simultaneously measure up to 50 properties of each immune cell in the blood samples.

They counted the types of immune cells, assessed what signaling pathways were most active in each cell and determined how the cells reacted to being stimulated with compounds that mimic infection with viruses and bacteria.

"This algorithm is telling us how specific immune cell types are experiencing pregnancy," Gaudilliere said.

They saw that natural killer cells and neutrophils have enhanced action during pregnancy.

The researchers also uncovered several previously unappreciated features of how the immune system changes, such as the finding that activity of the STAT5 signaling pathway in CD4+T cells progressively increases throughout pregnancy on a precise schedule, ultimately reaching levels much higher than in nonpregnant individuals.

The research appears in journal of Science Immunology.