There's a reason why many expectant moms think there's no such thing as a due date. Doctors are still using a method conceived in the 19th century, basing the calculation on the first day of a woman's last period. The other method, the ultrasound, can also be problematic because it gives less reliable information as a pregnancy progresses and doesn't predict spontaneous preterm birth (not to mention the equipment and trained technicians needed makes this option really expensive).
Well, what if there were a less expensive way for pregnant women to predict Baby's due date, including knowing if the baby is at risk of being a preemie (a baby that arrives at least three weeks early)?
That possibility is nearing reality, according to studies led by a team of researchers at Stanford University. According to the press release, new blood tests could show the stage of a baby's development in the womb and predict with 75 percent to 80 percent accuracy whether a pregnancy will end in premature birth. Added bonus: It's a "noninvasive" method that's cheaper than an ultrasound.
The small but significant studies, published in the journal Science on Thursday, were led by Stanford's Stephen Quake, who invented the first noninvasive prenatal blood test for Down syndrome and whose daughter was born almost a month premature.
Though his daughter is now 16 and doing well, the preemie experience stuck with the dad, who hopes the tests could help understand and reduce preterm births. Preterm births affect about 15 million infants worldwide each year and 9 percent of U.S. births. Two-thirds of the premature births are spontaneous (doctors usually don't know why these moms go into labor unexpectedly). Premature birth is also the largest cause of infant mortality in the U.S. Being able to predict preterm births can give parents the medical guidance they need as early as possible and help improve the baby's health.
To better predict a baby's birthday, the researchers collected weekly blood samples of 31 healthy pregnant women who had full-term pregnancies to measure the levels of cell-free RNA transcripts swimming in the women's blood—that is, the tiny bits of messenger molecule that carry the body's genetic instructions.
Dr. Edith Cheng, a professor of maternal-fetal medicine and medical genetics at the University of Washington, told the New York Times that RNA is like "a little bus that travels back and forth and is letting Mom know what’s going on." What's so cool to Cheng is that there's probably a molecular conversation going on, and researchers might get to the point where they'll find that Mom's responding.
In a related study with 38 women with elevated risk of delivering preterm, researchers found seven nucleic acids that accurately identified women who went into labor up to two months early. That is, in addition to the genes that give information about gestational age, there's also a handful of genes that might be signaling when Mom's "ready to pull the ripcord."
The results are preliminary and the researchers still have to validate the new tests with larger groups of pregnant women before they're ready for use, but damn is this exciting.
"I’ve spent a lot of time over the years working to understand preterm delivery," Mads Melbye, senior author of the study and the president and CEO of the Statens Serum Institute in Copenhagen, said in a statement. "This is the first real, significant scientific progress on this problem in a long time."