Genetic counseling and prenatal diagnosis

For patients referred for genetic counseling and possible testing:

Genetic counseling and prenatal diagnosis

You may be referred to our office for genetic counseling due to advanced maternal age (maternal age > 35 years old at due date), family history of genetic problems, concerning findings on fetal ultrasound or if your Down syndrome screen is abnormal.

Our physicians are experienced in providing genetic counseling and performing prenatal diagnostic procedures such as amniocentesis and chorionic villus sampling.

We will take a detailed family history from both the mother and the father of the fetus and discuss certain genetic problems that are more common in certain ethnic groups.  Once your history is obtained and any blood test or ultrasound results are reviewed, you may be offered amniocentesis or chorionic villus sampling.  The risks and benefits will be discussed with you.

The decision whether or not to have a procedure is a personal choice.  Many women will choose to have these procedures either based on their age, abnormal ultrasound or blood test results, because of a family history of a genetic or chromosome disorder or for peace of mind. 

Chorionic villus sampling (CVS)
CVS is performed between 10-14 weeks of gestation.  It is a procedure used to obtain placental villi and involves passing a catheter through the mother's cervix (transcervical CVS) or entering the mother's abdominal and uterine walls with a needle (transabdominal CVS).

Amniocentesis
Amniocentesis is performed between 15-22 weeks gestation.  It involves entering the uterine cavity through the mother's abdominal and uterine walls with a thin needle.

 

 

 

 

Blood testing
We offer carrier testing for genetic disorders such as cystic fibrosis, Fragile X and many others.  For uncommon or rare disorders, there are a few specific labs located around the country that will run these tests.  Those samples may need to be sent to outside labs and may not be covered by all insurance carriers.  Please contact your insurance carrier to ensure coverage.

 

 

 

Test results

The routine result of amniocentesis and CVS is called a karyotype.  A karyotype will show whether the number of chromosomes is normal, if there is one missing or if there is one extra.  It does not routinely test for the thousands of genetic syndromes that are possible in humans.  Testing may be targeted based on your family history or certain ultrasound findings. 

Neither CVS nor amniocentesis tests for birth defects.  Birth defects are diagnosed by ultrasound.  It is important to understand that neither of these tests guarantees a “normal” baby. 

You will receive a call from our office for any abnormal chromosome result.  Karyotype results will be available within 10-14 business days.  FISH tests will be available in three business days. Results of FISH testing will be called to you regardless of whether it is normal or abnormal.   Your obstetric provider will receive a copy of all test results once they have been received and reviewed by our physicians.