One in 10 babies is premature, a test predicts the risk

A blood test has been developed to predict the risk of premature birth more than four months before the expected due date: the test is based on the presence of certain fragments of free RNA in the blood (cfRNA) of the pregnant woman; women who will have a premature birth present a very distinct and recognizable profile of these circulating RNAs at 16 weeks of gestation, so much so that the 'liquid biopsy' is a potentially usable test to be used alongside other prenatal tests that are routinely performed today. This is the result of a study conducted at BGI Research in Shenzhen and the Hospital of Obstetrics and Gynecology of Fudan University in Shanghai, China, which will be presented at the annual conference of the European Society of Human Genetics held in Milan.

Every year, approximately 13.4 million newborns worldwide are born prematurely, accounting for about one in ten of all live births. Nearly one million of these preterm infants die each year, and PTB remains the leading cause of mortality in children under five. According to data from SINPIA, the Italian Society of Child and Adolescent Neuropsychiatry, every year in our country between 25,000 and 30,000 newborns are born prematurely, approximately 1 in 10 children, most of whom are not severely premature (so-called "late preterm"), while approximately 0.9-1% are born "very" or "extremely" preterm. Since children born preterm have immature organs that are not yet prepared for life outside the womb, the risk of complications is much higher than those born at term. This can lead to a number of health problems such as respiratory problems, jaundice, feeding difficulties, and infections. The long-term health problems of these children include cerebral palsy, epilepsy, and blindness, and they place a significant emotional and financial burden on their families. Predicting the risk of preterm birth (PTB) and then implementing preventive strategies is difficult, in part because of the lack of reliable predictive tools. The experts analyzed blood samples from 851 pregnant women (299 PTB cases and 552 controls) at about 16 weeks of gestation and found significant alterations in the cfRNAs of women who would later experience preterm birth; the RNA profile was different in pregnant women who went on to term. The study included both preterm births with intact membranes and premature rupture of membranes (when the water breaks before labor begins), with less than 3% of women having had a previous preterm birth.

Being able to detect these predictive signals over four months, when there is still no clinical recognition of the risk of preterm birth, could revolutionize prevention strategies. "In essence, our method uses the same blood sampling times as routine noninvasive prenatal testing (NIPT), allowing for double testing," the authors explain. Current costs of cfRNA sequencing are similar to those of NIPT, but are expected to decrease. This creates a potential path for both monitoring high-risk patients and broader population-level screening," the authors say.