Impressive new research led by a team from the Stanford University School of Medicine has discovered a set of biomarkers that can predict when a pregnant woman will go into labor several weeks in advance. It's hoped the breakthrough findings can be translated into a predictive blood test within the next few years.
“Clinicians are good at estimating gestational age, which measures the development of the fetus,” explains senior author on the new study, Brice Gaudilliere. “But there is a disconnect between this timing and when labor starts, because whether the baby is ready is only one factor in the onset of labor. The other part of the equation is the mother.”
Although we know an average pregnancy lasts around 40 weeks, its considered normal for a woman to go into labor anytime between 37 and 42 weeks. And, over 10 percent of pregnancies end in pre-term birth, earlier than 37 weeks.
This robust new research, published in the journal Science Translational Medicine, tracked the last 100 days of pregnancies in 63 women. Blood samples were taken at various points and over 7,000 metabolic and immune biomarkers were analyzed.
Mathematical modeling allowed the researchers to home in on several specific factors that were seen to consistently correlate with a transition to labor. Unsurprisingly, there were surges in steroid hormones and increases in placental hormones. But one of the most novel and exciting discoveries was a rise in an immune protein called IL-1R4.
This particular immune protein has anti-inflammatory properties and the research noted its levels seem to rise around two to four weeks before a woman goes into labor. It’s hypothesized that this anti-inflammatory response is how the body tamps down the immune system as higher levels of placental material reaches a mother’s bloodstream in the weeks before giving birth.
“The hypothesis has been that labor is an inflammatory reaction, and yes, there are signs of that,” says Gaudilliere, “but we also found that aspects of this inflammation are toned down before labor starts, which we think may prepare the mother’s immune system for the next phase, when the baby is born and healing and immune resolution begins. It needs to be a regulated process.”
This physiological shift detected in the study was independent of gestational age or ultimate duration of pregnancy. This means detecting this transition could allow doctors to catch pregnancies that are turning premature before a woman gives birth. And at the other end of the spectrum, it could be possible to detect late-term pregnancies that are not moving into labor and induce the birth sooner.
“The mom’s body and physiology start to change about three weeks before the actual onset of labor,” explains co-author Virginia Winn. “It’s not a single switch; there’s this preparation that the body has to go through.”
At the moment, the model developed can only narrow its predictions to a two-week window. However, the researchers claim with further investigation and validation this will become much more precise, and they expect an effective test to appear within the next few years.
The new study was published in the journal Science Translational Medicine.