'New blood test may predict premature birth risk'

Sunday, 10 Jun, 2018

This is much less expensive than standard ultrasound procedures. Recently released provisional data for 2017 from the National Center for Health Statistics show that the preterm birth rate in the USA has reached 9.93 percent, up from 9.86 in 2016, the third consecutive annual increase after steady declines over the previous seven years.

Parents have long yearned for a simple test that could accurately predict a mother's due date, and her risk of a premature birth.

In the pilot study, which involved 31 healthy pregnant women, the blood test predicted gestational age with an accuracy that's comparable to that of an ultrasound, but at significantly cheaper costs.

Researchers, led by Professor Steven Kueik of Stanford University, California, who published the journal Science, found a new method that predicts the activity of certain maternal and fetal genes as biomarkers.

Stevenson, M.D., principal investigator at the March of Dimes Prematurity Research Center at Stanford University, describes the PCR-based tests, which can be carried out on a single blood sample, as effectively "eavesdropping on a conversation" among the mother, the fetus, and the placenta.

Researchers were able to identify differences in RNA levels from seven genes between the two groups of women, accurately predicting which pregnancies would end up in preterm births up to two months prior to labor.

Prof Basky Thilaganathan, a Royal College of Obstetricians and Gynaecologists spokesman, said: "Complications from premature birth are a leading cause of infant mortality and affect 7-8% of all births in the UK".

"RNA corresponding to placental genes may provide an accurate estimate of fetal development and gestational age throughout pregnancy", the report found.

"Our test was able to predict 80.3% of women who went on to have any preterm birth, at 15 to 20 weeks gestation", Laura Jelliffe-Pawlowski, an associate professor and director of Precision Health and Discovery at the University of California, San Francisco's Preterm Birth Initiative and coauthor of the study, tells CNN. He added that today's findings affirm the existence of a "transcriptomic clock of pregnancy" that could serve as a new way to assess the gestational age of a fetus. Further development and validation of an initial model resulted in the identification of a panel nine placenta-specific RNAs (CGA, CAPN6, CGB, ALPP, CSHL1, PLAC4, PSG7, PAPPA, and LGALS14) in maternal blood that could predict gestational age. They noticed that levels of some genetic messenger molecules, called RNA, changed as the women's pregnancies progressed.

The scientists need to validate the new tests in larger cohorts of pregnant women before they can be made available for widespread use.

For the study, the team used blood samples collected during pregnancy to identify which genes gave reliable signals about gestational age and prematurity risk.

These women each gave a blood sample during the second or third trimester of their pregnancies. If larger clinical trials reproduce them, this kind of blood test could help save babies who would otherwise die because they were born prematurely, the researchers say.