Researchers from Standford University have developed a new blood test for pregnant women that may detect whether their pregnancies will end in premature birth. The technique can also be used to estimate a foetus’s gestational age or the mother’s due date as reliably and less expensively than ultrasound.

There have been several studies on preterm births in the past, and the reasons for it. A study by the University of Pennsylvania linked such births to changes in the mother’s bacteria. Another study by CHU Sainte-Justine in Canada found that having a baby later in life could increase risk of preterm birth.

“This new research is the result of a collaboration between researchers around the world,” said co-author Stephen Quake, Professor at the Stanford University in US. The findings, published in the journal Science, suggested that the tests could help reduce problems related to premature birth, which affects 15 million infants worldwide each year.
The tests measure the activity of maternal, placental and foetal genes by assessing maternal blood levels.

According to the researchers, until now, doctors have lacked a reliable way to predict whether pregnancies will end prematurely, and have struggled to accurately predict delivery dates for all types of pregnancies. The tests measure the activity of maternal, placental and foetal genes by assessing maternal blood levels of cell-free RNA, tiny bits of the messenger molecule that carry the body’s genetic instructions to its protein-making factories.

For the study, the team used blood samples collected during pregnancy to identify which genes gave reliable signals about gestational age and prematurity risk. The gestational-age test was developed by studying a cohort of 31 women who gave blood weekly throughout their full-term pregnancies.