Mother's Blood Could Offer Insights Into Fetal Health

Mar. 23 -- FRIDAY, Sept. 21 (HealthDay News) -- Just a small amount of a mother-to-be's blood could become the lens through which doctors monitor various stages of fetal health and development, a new study suggests.

"It's amazing that all these pregnant women are walking around with the answers in their blood," said Dr. Jill L. Maron, the study's lead author and an assistant professor of pediatrics at Tufts-New England Medical Center, in Boston.

Maron was referring to the fetal genetic material (mRNA) that, according to the study, circulates in a pregnant woman's blood prior to birth. The ability to open this window on fetal status by taking a sample of the mother's blood "can advance the field of prenatal diagnosis," she said.

It could also represent an important advance in the prenatal diagnosis of genetic diseases and genetic monitoring of fetal development because it wouldn't require invasive procedures, such as amniocentesis.

Another advantage of being able to detect fetal mRNA in the mother-to-be's bloodstream is that "it's dynamic," meaning that the biomarkers expected to be found would vary with time and stage of fetal development, Maron added.

DNA is the genetic material that's common to every cell, Maron said. RNA determines what is transcribed from the DNA to make an eye cell different from, say, a hair cell, she said.

"RNA is more real time. RNA changes all the time, according to the stage of development. That dynamic nature is what we're targeting," Maron said.

The researchers said they proved the presence of fetal mRNA in maternal blood in three ways.

Before delivery, the researchers found that the whole blood of nine mothers included fetal genes, such as those for development, sensory perception, and neonatal physiology.

Then the researchers established that these fetal genes found in the mother's blood were unique to the fetus by also identifying them in umbilical-cord blood.

Finally, within 24 to 36 hours after delivery, these fetal genes were no longer found in the mother's blood, providing additional confirmation that they were unique to the fetus, according to the study.