Published: Sun, June 10, 2018
Medicine | By Douglas Stevenson

Blood test may predict premature birth

Blood test may predict premature birth

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. "With further study", Dr. Stevenson suggests, "we might be able to identify specific genes and gene pathways that could reveal some of the underlying causes of preterm birth, and suggest potential targets for interventions to prevent it".

The test, described in a paper publishing online today in Science, is a big step forward for babies. 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). Preterm births affect about 15 million infants worldwide each year and 9 percent of US births. 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.

And it is hard to accurately predict delivery dates, she said.

Preterm births is the largest cause of infant mortality in the United States.

This is why the latest research findings are so groundbreaking for women and infants.

Stanford and Danish researchers examined the blood of more than 31 women every week during their pregnancies.

The scientists used blood samples from 21 of them to build a statistical model, which identified nine cell-free RNAs produced by the placenta that predict gestational age, and validated the model using samples from the remaining 10 women. "The model's two most important features, CGA and CGB, encoding chorionic gonadotropin α and β3 subunits of human chorionic gonadotropin (HCG), are known contributors to pregnancy initiation", the authors point out. The study was led by Stephen Quake of Stanford University, who said that the test could provide a low-priced method of estimating a fetus' gestational age.

Until now, some tests for predicting premature birth were available but they tended to work only in women at high risk, and were accurate only about 20% of the time, according to the report. In validation tests in an independent cohort, they found that "the test accurately classified four of five preterm samples (80%) and misclassified three of 18 full-term samples (17%)". 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.

The study to predict women's due dates included expectant mothers in Denmark who submitted a blood sample each week throughout their pregnancies.

Now, using powerful genetic techniques, Stanford scientists are closing in on that dream with a preliminary tool that requires only a pregnant woman's blood sample. These tests hold promise for prenatal care in both the developed and developing worlds....

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