Doctors measure length of fetuses’ noses to look for disorders

For years expecting mothers have had to wait until the latter part of their pregnancy to detect fetal abnormalities like Down syndrome. But now there’s a method for earlier detection, and it does not involve drawing blood or amniotic fluid.

Normally, a woman would have to wait up to five months to find out her baby will be born with a chromosomal disorder like Down syndrome. And she would have to have the invasive amniocentesis. Now, women can learn as early as ten weeks into the pregnancy if there’s a chance their baby will have Down syndrome. Doctors are doing this by measuring the length of the fetus’ nose as well as the thickness of the skin on the back of the neck. Doctors use an ultrasound.

Doctor David Colombo is an assistant professor of maternal fetal medicine at the Ohio State University Medical Center. He said only a few hospitals around the country use this technique.

“There’s no one thing that you can look for to say the baby has or doesn’t have a problem. We know the kids with Down syndrome tend to have an absent or very small nasal bone as opposed to the majority of infants at that gestational age. If there’s say a small or absent nasal bone and the thickness, the neucotranslucency is thickened, those would be two signs this baby is more likely to have a problem like Down syndrome,” Colombo said.

Neucotranslucency is the skin on the back of the neck. Colombo said not all babies with a smaller than normal or absent nose bone will be born with Down syndrome. He said these measurements are not a definite determinate.

“We take all the information and put it together and come up with a single risk. And then the parents take that risk and determine if that’s a high value or low value. If they say, you know, that risk is higher I’d really like to know if my baby has a problem then you’d do the diagnostic test like, CVS or biopsying the placenta, or take amniotic fluid like an amniocentesis,” Colombo said.

OB/GYN resident at OSU, Shavonne Ramsey-Coleman is 11 weeks along in her pregnancy. Ramsey-Coleman offered to have Colombo measure the length of her baby’s nose and thickness of the skin on the back of the neck. Her baby is only an inch long at this stage.

“The nasal bone is this small structure right there. And it is one millimeter, one and a half millimeters long. So this baby has a normal nasal bone. So if we’re going to look at the thickness of the skin on the back of the baby’s neck,” Colombo said.

Colombo said based on these two findings, Ramsey-Coleman’s risk for having a baby with Down syndrome is low. If she were actually having a full procedure, certain chemical levels would be taken in her blood and all of the information would be put together for a total risk level.

Ramsey-Coleman, who is carrying her first child, likes the measurement technique.

“I think it’s more to put my mind at ease. I’m under 35 so I know my risk is a little bit lower. But being in the specialty I think you worry a little bit more, and I think it will give me peace of mind,” Ramsey-Coleman said.

OSU offers this technique to all pregnant women having an ultrasound.

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