Stanford University researchers have discovered blood markers that suggest when the time for birth is coming.
Is it possible to predict when a pregnant woman will give birth? Yes, according to a team of Stanford University experts who demonstrate that the moment of delivery can be established by examining immunological and other biological markers present in a blood sample.
The research, published in the journal Science Translational Medicine, is the first to provide light on how labor begins, a biological process that has hitherto been a mystery.
Furthermore, the findings pave the way for the development of a blood test that could predict when a baby will be born – the time of delivery. Current predictions are imprecise, and anything within a five-week window, from three weeks prior to the expiration date to two weeks beyond it, is deemed typical.
The researchers expect that their findings will help them develop a test to forecast the onset of labor in healthy pregnancies in the next two to three years.
“We found a transition from ‘progressing pregnancy’ to a ‘pre-labor’ phase that happens two to four weeks before the mom goes into labor,” said Ina Stelzer, PhD, the study’s lead author and a postdoctoral scholar in anesthesiology, perioperative and pain medicine at Stanford. “We’ve identified a novel way to use the maternal blood to predict when a mother will go into labor. This prediction is independent from the duration of pregnancy.”
His method was effective for both full-term pregnancies and premature deliveries.
The study discovered that changes in steroid hormone levels, proteins that affect blood vessel formation and blood clotting, and immune regulation signals describe the shift to maternal biology before delivery.
“The mom’s body and physiology start to change about three weeks before the actual onset of labor,” said co-author Virginia Winn, MD, PhD, associate professor of obstetrics and gynecology at Stanford. “It’s not a single switch; there’s this preparation that the body has to go through.”
Doctors currently calculate a woman’s due date by calculating 40 weeks from the first day of her last menstrual period and factoring in information from ultrasound procedures about the baby’s size.
“Clinicians are good at estimating gestational age, which measures the development of the fetus. 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,” said Brice Gaudilliere, MD, PhD, the study’s senior author and associate professor of anesthesiology, perioperative and pain medicine. “The other part of the equation is the mother.”
Despite the fact that most women give birth around 40 weeks of pregnancy, delivery between 37 and 42 weeks is deemed normal. For both medical and planning purposes, a more exact forecast of when the baby will arrive would be beneficial. Knowing if a woman with preterm contractions is in the prepartum phase, for example, could help doctors determine whether or not to give her steroids to mature the foetal lungs before birth.
63 women were monitored for the last 100 days of their pregnancy in this study. Two or three times before delivery, they took blood samples for analysis. They all went into labor on their own, which means they weren’t forced into it.
Each blood sample was examined for 7,142 immunological features, including unicellular, protein, and metabolic. The researchers used mathematical models to figure out which blood parameters best predicted the start of labor.
58 of the women gave birth after full-term pregnancies, which means the baby arrived no more than three weeks before the due date, and five gave birth after spontaneous premature birth.
The woman’s blood exhibited spikes in steroid hormones including progesterone and cortisol as they advanced into the prepartum phase, corroborating prior results on the biology of late pregnancy. The blood also exhibited decreasing amounts of factors that promote blood vessel construction, which is likely a first step toward diminishing the placenta-uterus connection, as well as increasing levels of blood clotting factors, which assist reduce blood loss after delivery. Some placental proteins rose as well.
The researchers also discovered a fine-tuning of immune responses throughout the transition to labour preparation. According to the researchers, the highest predictive feature in the model was IL-1R4, a regulatory immunity protein that controls an inflammatory cytokine called IL-33.
Placental material and fetal cells reach the mother’s blood at the end of the pregnancy, perhaps triggering an immunological reaction. According to Stelzer, the body must carefully control the quantity of inflammation that occurs during childbirth.
“The hypothesis has been that labor is an inflammatory reaction, and yes, there are signs of that, 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,” Gaudilliere said. “It needs to be a regulated process.”
The findings could have other important clinical implications, Winn adds: “If we understand what’s regulating labor, we might be able to do a better job of inducing labor.”
Image Credit: Getty
You were reading: This blood test can predict the exact date of your child’s birth