Chorionic villus sampling; a test not for everyone

I look into the faces of my children and I can honestly say without hesitation that I would not change anything about how my life has played out.  There were times when Ben’s fate was unclear that I thought about what I would have done had I known early in my pregnancy about Ben’s chromosomal disorder.  This subject is so controversial and so PERSONAL.  No one can know exactly how they will react to news that their unborn child may have life threatening problems.

 Early testing that now can be done can leave parents with choices that may not have been available thirty or forty years ago.  Some parents I talk to consider it to be a double-edged sword.  Others look at it as not any kind of choice but as additional information that will help them to prepare for the arrival of their new family member.  Regardless of how it is characterized CVS testing can be a very informative mode of early testing for a pregnant mother.  A majority of mothers who undergo CVS testing find out that their babies have normal chromosomes.  This can reduce the stress that high-risk mothers must deal with when wondering about the fate of their unborn babies.  This was certainly true in my case.

 So what exactly is Chorionic villus sampling.  It is a form of prenatal diagnosis that is done one of two ways.

  1. Transcervical: An ultrasound guides a thin catheter through the cervix to your placenta. The chorionic villi cells are gently suctioned into the catheter. This is the most common method.
  2. Transabdominal: An ultrasound guides a long thin needle through the abdomen to your placenta. The needle draws a sample of tissue and then is removed. This procedure is like that of amniocentesis.

I can say from experience…. NOT FUN!

Chorionic villus sampling (CVS) detects chromosomal abnormalities such as trisomy 9, as well as a host of other genetic disorders. The doctor takes cells from tiny fingerlike projections on the placenta called the chorionic villi and sends them to a lab for genetic analysis.  The test is usually done with either PCR or FISH. The polymerase chain reaction (PCR) is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders detect and localize the presence or absence of specific DNA sequences on chromosomes.   FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high degree of sequence complementarity.   CVS usually takes place at 10–12 weeks’ gestation, earlier than amniocentesis (14–16 weeks).   

The most compelling argument against CVS is the slightly higher instance of miscarriage that results from the performance of the test.  It is up to each person to make a decision about the advantages and disadvantages of this controversial form of testing.

This entry was posted in Disabilities, Intellectual Disabilities, Intellectual Disabilities, Special Needs, Trisomy, Trisomy 9, trisomy9 and tagged . Bookmark the permalink.

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