Amnio & CVS, Why You Might Consider These
By NurseBarb on August 14, 2013
Many couples wrestle with the overwhelming amount of decisions in pregnancy. Should they have genetic testing and if so, what kinds. Should they have ultrasounds, Amnio or CVS, new NIPT.
Amnio & CVS are 2 tests that are available, however, our recommendations for who needs these are changing based on new genetic tests that are available. These tests are considered diagnostic, with high levels of accuracy in assessing pregnancies with serious genetic conditions. Until recently, any woman over 35, most of whom were 99% likely not to have an affected pregnancy were offered these potentially risky, invasive tests.
Why women were offered Amnio & CVS
We used to offer Amnio & CVS to women just based on their age. If they were over 35, we considered that their risk of having a pregnancy with Down Syndrome or other serious genetic condition was increased from what it was in their 20's, approximately 1 in woman out of every 1 - 2 thousand to 1 in 300. As women get older their risk increases. And yet, the risk is still quite low.
Why False Positives are a Concern
Then, about 10-15 years ago, we started using ultrasounds combined with blood tests for pregnancy proteins and hormones timed at various stages of pregnancy to assess risk. These tests were better than just guessing based upon age, but still had high rates of false positives ( 5%).
Receiving a positive result with the combined and integrated screening also meant waiting weeks for more testing or traveling to see a specialist, both of which causes a lot of worry and anxiety. In addition, amnio & CVS can cause miscarriage, an added risk and worry.
Now, with NIPT, which is much more accurate in screening for genetic conditions, fewer women will be offered these potentially risky diagnostic tests. With NIPT, a simple blood test at 10 weeks can give couples a high level of accuracy of over 99% in screening for serious genetic conditions, with a low false positive rate of less than 0.1%.
Preparing for Medical Conditions
Many families choose to have an amnio, knowing that they would not terminate, as a way to be better prepared in case their child needs specialized care soon after the birth. Many children with genetic conditions will need support and various treatments throughout their life.
Over half of babies born with Down Syndrome, trisomy 21 or other serious genetic conditions have significant health challenges. The Down Syndrome Pregnancy Organization and Brighter Tomorrows have a wealth of helpful information.
Some families will chose to terminate a pregnancy that's affected with a serious genetic condition. It's an understatement to say that this is a highly personal and private choice that each woman and each family will make based upon a number of factors.
The resources listed above can help every family.
I also recommend to my patients, who know that they wouldn't terminate that they consider having a diagnostic amnio so to help them prepare emotionally. Parents have to work through the "shock" of finding out that they are having a baby with challenges. This is a normal and natural reaction that each family will work through in their own way.
My patients who have been through these challenges have encouraged me to emphasize how important it is to grieve the loss of the "child of their dreams" and so that they can get busy loving and caring for their new baby.
Results and Decisions
After people learn their results, they then have the opportunity to review and re-evaluate their feelings and their decisions. Again, this is a highly personal decision and parents need time to think about the long and short term effects on every aspect of their lives. Thinking about what they would do when Down Syndrome is only a possibility may be very different than when it is a reality.
Many families who receive the news that they are carrying a baby with Down Syndrome or other serious genetic abnormalities do not change their minds and continue their pregnancy. There are others who decide differently. Neither decision is easy, and all families should be supported through their journeys.
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