Prenatal Genetic Screening Tests: Nuchal Translucency And Blood

Once you’ve discovered you’re pregnant, the joy and wonder you feel for the new life growing within you may sometimes be diminished by worries about whether or not your new baby will be born healthy. You may start to recall every single piece of junk food you’ve ever eaten or every time you’ve somehow found yourself in a smoke-filled room and wonder if your unborn child has been affected in some way. Every expectant mother hopes that her baby will be healthy at birth and, in fact, the vast majority of babies are. Since 96 to 97 out of every 100 babies are born healthy, there is little real cause for concern.

However, these numbers also mean that the other 3-4% of all babies born will have some type of defect. To any expectant mother, the thought of your new baby being anything less than perfect can be heartbreaking, but it’s important to note that not all birth defects are severe. Many defects are treatable, often immediately following birth or, in some cases, even before the baby is born. Other defects can be of a more serious nature.

Do all you can to insure the health of your unborn child. Call HEALTH CARE FOR WOMEN in Salinas, CA to learn more about the importance of proper prenatal care during your pregnancy.

The Difference Between Screening And Diagnostic Tests

Prenatal testing to detect genetic abnormalities in the fetus fall into two different categories: screening and diagnostic. Screening tests, like a nuchal translucency scan, do not diagnose the presence or absence of disease. Instead, the nuchal translucency scan is used as an indicator of whether the possibility of disease is higher or lower than the norm – it doesn’t provide a diagnosis, but it can assess your baby’s risk for certain problems. Diagnostic tests, such as an amniocentesis are used to verify, or diagnose the presence of disease.

Who Should Be Screened?

Statistically, the chances of a baby having Down syndrome are related to the age of the mother. For mothers under the age of 25, the chances of having a child with Down syndrome are 1 in 1,400. At the age of 35, the chances are now 1 in 350. At the age of 40, the odds are about 1 in 100. Because of these statistics, the age of the expectant mother has always been factored into the decision to pursue screening for genetic abnormalities. Now however, the American Congress of Obstetricians and Gynecologists recommends that women of all ages be offered first and second-trimester screening and diagnostic testing options.

The Nuchal Translucency Screening or NT screening

Doctors began using this type of prenatal screening in the mid-nineties and the Nuchal Translucency Screening, or the nuchal scan, has been in widespread use since 2003. This relatively new, but very effective, screening tool is performed during your first trimester, usually along with a maternal blood test in order to safely evaluate the possibility that a genetic disorder or heart defect may exist in the developing fetus.

This procedure is non-invasive and safe. Perhaps your biggest challenge will be the level of anxiety you may experience when thinking about ”what might be”. Try to remember that the odds of you having a healthy child are overwhelmingly in your favor. Again, the NT screening isn’t a diagnostic test. The results of the nuchal scan, combined with other factors that may or may not statistically place the fetus in a higher risk group, simply indicate whether or not additional testing (diagnostic) would be advised.

Using high-resolution ultrasound equipment, your doctor or sonographer will first verify your baby’s fetal age by measuring your baby from crown to rump. This is critical to the accuracy of the NT screening because during weeks 11 to 14, the base of your baby’s neck – the nuchal fold – is still transparent and the amount of fluid can be accurately measured. After 14 weeks, the nuchal fold becomes less transparent and the continuing development of your baby’s lymph system may drain the amount of excess fluid in the nuchal fold, allowing possible abnormalities to go undetected.

Once the baby’s fetal age has been verified, your doctor then locates and measures the size of the nuchal fold. A larger-than-normal nuchal fold indicates excessive fluid in the area which may mean your baby may be at increased risk of having a genetic abnormality.

Health Care for Women in Salinas, California performs Nuchal Translucency screenings. The doctors there can answer any questions you may have about prenatal testing, maternal blood tests, or for any other questions or concerns you may have concerning gynecology, obstetrics, healthy pregnancies or general women’s healthcare, please call 831-758-8223, or visit the Health Care for Women website and get in contact today.

Maternal Blood Test

Typically, the NT screening is performed along with a maternal blood test. The blood sample is tested for specific indicators that are only present during pregnancy, as the NT measurement alone cannot be used for risk assessment. These test results return either ”Screen Negative”, indicating the pregnancy is at a low risk of Down syndrome (Trisomy 21) or Edward’s syndrome (Trisomy 18), or ”Screen Positive” which means the mother is in a higher risk group.

These results, used in conjunction with the nuchal scan, provide clear indicators of whether or not additional diagnostic testing would be advised. Again, it is important to note that, based on these indicators alone, you shouldn’t assume that you are carrying a child with a genetic abnormality. These indicators also do not conclusively prove that you are not. These tests are simply another tool to help evaluate the possibility of your baby having a genetic abnormality and whether diagnostic testing is advised.

Diagnostic Testing

If the results of these tests indicate that your baby may be at a higher risk of having a genetic abnormality, then diagnostic tests, such as an amniocentesis should be considered. Further testing allows you to confirm your baby’s condition. If a diagnosis is confirmed, this will provides you with the opportunity to:

  • Begin planning for raising a child with special needs
  • Anticipate changes in your lifestyle that may be required
  • Locate resources and support groups
  • Decide whether or not to carry the child to full term.

As soon as your pregnancy is confirmed you will want to discuss with your ob gyn the different prenatal tests and procedures that are available in order to properly assess your baby’s health and development. Each of these tests and procedures has its own unique advantages, disadvantages and limitations. At this stage of your pregnancy, your doctor’s training and experience will serve as an invaluable tool to help you understand everything you need to in order to make an informed decision about which screenings and tests you would want to pursue in order to do all you can for the health of your unborn child. Talk to your obstetrician, ask questions and gather as much information as you can.

If you are interested in learning more about Nuchal Translucency Screening, or you would like to schedule a nuchal translucency screening, please contact Health Care For Women at our Salinas office or by filling out a Quick Contact on their website at

Getting Help

The feelings that many parents experience when they discover they have a child diagnosed with Down syndrome can be overwhelming. Learning all you can about Down syndrome may help to alleviate some of your fears and questions about the future.

There are a variety of excellent resources available today to help you. Check with your doctor or a social worker to learn what resources are available in your area.

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