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New Prenatal Test Reveals Genetic Disorders and a Surprise

A new type of prenatal screening can tell parents with more than 99 percent accuracy whether their baby will be born with a genetic abnormality, such as Down syndrome. It's called MaterniT-21, and it can be done as early as 10 weeks into the pregnancy.

Robin Adkins-Vosler is a planner. At just 11 weeks, she’s hardly even showing. Already, her unborn son or daughter, has an extensive wardrobe

“Literally, probably for already the last year, I have been buying baby clothes,” Vosler says, ”I find designer baby clothes in Salvation Army all the time.”

Baby clothes aren’t the only thing Vosler needs to plan for. By the time she delivers her first child in August, she’ll be 35.

“At the first OB visit, my doctor sat us down and explained to us that I would be considered advanced maternal age, which is being 35 at delivery,” Vosler says.

“Advanced maternal age” means Vosler is at higher risk for having a baby with Down syndrome or another genetic disorder. Vosler’s doctor recommended she have a new type of screening test that analyzes the DNA of the unborn baby. Sounds complex, right? Vosler says not so.

“They literally draw your blood. And that’s it,” Vosler laughs, “It’s that simple.”

Past tests have been invasive. Amniocentesis is a procedure used to obtain a small sample of amniotic fluid by injecting a long needle through the belly button.

The procedure was a scary idea for Vosler, for many reasons.

“It even had a small chance that it could cause a miscarriage, just to test for Down syndrome,” she says.

Also, the older tests gave only a probability that the baby would be born with a genetic disorder. Some parents stressed over what turned out to be a false positive. Dr. Jerry Yankowitz, who chairs the department of obstetrics and gynecology at the University of South Florida, explains the new screenings are more than 99 percent accurate.

“The older tests were looking for chemicals produced in the baby’s body or the placenta or an interaction with the mom,” Yankowitz says, “it was a very indirect test of whether there was something genetically wrong.’

He says the difference between the tests is that the new test, looks directly at the baby’s genetic material. One main reason it’s not 100 percent accurate is that the genetic material floating in the mother’s blood is 90 percent hers and only 10 percent the baby’s.

He says they use really complicated biochemical analysis and computers, or supercomputers, to sort out the various ratios.

Abnormalities aren't the only thing the test picks up: the screening, can reveal the baby’s gender as early as 10 weeks. That’s more than a month sooner than traditional ultrasounds. This has some low-risk moms shelling out $400 or $500 for so-called “boutique” blood tests to learn the sex of their baby.

Vosler and her husband, Jason, learned the gender of their baby -- who tested negative for Down syndrome, by the way -- live on NBC’s Today show as part of a story on the new screening.

Vosler and her husband will spend the next couple of months preparing for the arrival of their healthy baby boy.

Dalia Colón is excited to return to WUSF as producer of the Zest podcast. From 2010 to 2014, Dalia covered health and features for WUSF. Before that, she was a staff reporter for the Tampa Bay Times and Cleveland Magazine.