Vanguard

Issue date: 11/25/03 Section: News

John Adams/University Photographer [Click to enlarge]

The University of South Alabama Center for Women's Health is offering yet another "first" for pregnant women in the community. After premiering the 4-D ultrasound less than a year ago, USA is the first center in the state certified to offer a unique, noninvasive test to detect Down syndrome and other chromosomal abnormalities in the first trimester of pregnancy.

When the fetus is between 11-14 weeks gestation (11-13 weeks plus six days), sonographers use an ultrasound to measure nuchal translucency, or the thickness of skin at the back of the fetal neck. This area is normally clear in healthy fetuses, but the tissue tends to thicken in fetuses with abnormalities due to accumulation of fluid at the back of the neck.

The UltraScreen is the combination of nuchal translucency measurement and a blood test that uses the mother's blood taken from a simple finger stick. The combination of these two tests is more than 90 percent accurate in detecting Down syndrome and 97 percent accurate in detecting Trisomy-18 (generally lethal anomalies that are more obvious to detect).

The UltraScreen, however, is also effective in detecting defects other than chromosomal abnormalities, including heart problems and skeletal dysplasias.

"It has actually been a marker for more defects than they realized," said Dr. Kathy B. Porter, chair of the USA Department of Obstetrics and Genecology and division head of maternal-fetal medicine. "We've been able to detect a number of birth defects and heart abnormalities. As the baby gets large enough that we can see the heart, we can keep an eye on it if we have an abnormal nuchal translucency." Porter said this information helps them to prepare to deliver at a hospital that can accommodate a baby with heart problems or other abnormalities.

In order to be certified, sonographers must be able to demonstrate "repetitive skill and ability to accurately repeat the measurement and get reliable results," Porter said.

USA is certified through the Fetal Medicine Foundation based in London, where nuchal translucency is a standard of care in Europe. Sonographers wishing to be certified must take a written examination and send their images and measurements to the London location. The Fetal Medicine Foundation will then determine if the sonographers passed the accreditation process, and they must get recertified every year.

"It's a time-consuming process," said Vicki Arguello, chief sonographer at USA. "Any sonographer in the community can actually measure nuchal translucency. That's not the tough part. The tough part is following through with the accreditation process."

If the staff is not accredited, the mother's blood work will not be accepted by the North Carolina lab, the U.S. site for accreditation. Without the blood work results, the nuchal translucency measurement is inconclusive.

Women who are advanced maternal age (35 and over) or women who are considered high-risk pregnancies are candidates for the UltraScreen. Rhonda Steiner, 22, is a patient at the USA Center for Women's Health. Although she is young, Steiner has a history of problematic pregnancies. Her first baby died from a diaphragmatic hernia, and her second baby was born with features suspicious of Down syndrome.

"My son was born, and they thought he had Down syndrome because of some of the features on his hands and his feet," Steiner explained. "Luckily he's fine, but I'm still considered high-risk, so they do every test they can."

Steiner's son is now 20 months old, and he is doing well. The nuchal translucency and blood test show Steiner's third baby is also doing well so far.

An advantage to using the UltraScreen is it provides an alternative to amniocentesis, an invasive procedure that uses a needle inserted into the mother's belly to draw a sample of amniotic fluid. It also provides an alternative to chorionoc villi sampling (CVS), an analysis of the genetic makeup of cells from fingerlike projections on the placenta. The UltraScreen also allows mothers to have the test performed earlier and the results quicker than before.

"I would much rather have a prick on the finger and an ultrasound where you actually get to your baby than a needle in the belly," Steiner said. "It does help ease my fears because you can find out a lot earlier than an amniocentesis. I had an amnio with my first baby, and it took about 14 days to get the results back. That's just a very stressful time. If we would have known those results, we wouldn't have been so worried."

Porter said, "There is opportunity to find out if your baby appears normal early on to reduce some of that anxiety. If all the tests look normal, then you may not have to undergo any invasive procedures. An amnio is 99 percent accurate, so it gives them a little more assurance, but it's never going to be absolute."

In addition to being noninvasive, the UltraScreen does not pose any risks to the mother or the baby. Approximately one in every 200 amniocenteses results in miscarriage, and one in every 100 CVS procedures results in miscarriage. Nuchal translucency measurement and blood test will greatly reduce the number of miscarriages of healthy babies.

The key to the UltraScreen's effectiveness is expectant mothers' willingness to cooperate. Arguello advises women to see their obstetrician as soon as they find out they are pregnant, especially mothers who are advanced maternal age.

"The test is 11-14 weeks, so we're working with a very small timeframe," Arguello said. "We always want to see a great, healthy baby and a good pregnancy, but it's important you come in early."

Steiner agrees with Arguello and tells expectant women in the community to do whatever is necessary to ensure a healthy baby and pregnancy.

"Don't be afraid to get whatever test done. If the tests do come back positive, then you can prepare yourself and deliver somewhere that can deal with your baby's problem," Steiner advises. "Or if everything comes back OK, then you don't have to worry about it, and you can just relax."

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