Chorionic villus sampling is also referred to as CVS.
Mainly this prenatal diagnostic test is used for recognizing chromosome abnormalities and any other genetic conditions.
Your healthcare provider will suggest this diagnostic method if you and your partner have any history of medical disorders.
Mainly this test is performed 10-13 weeks after your last menstrual period and before amniocentesis.
Chorionic villus sampling can be used to identify:
All types of chromosomal abnormalities: These diseases include sex chromosome abnormalities, trisomy 18, trisomy 13 and Down syndrome. This method is more than 99% effective.
All types of genetic disorders: The disorders include: cystic fibrosis, Tay-sachs disease and sickle cell disease. Chorionic villus sampling is used to inform you whether your child has this disease or not.
Performing Chorionic villus sampling:
In Chorionic villus sampling, the doctor removes the cell by using tiny fingerlike projections on the placenta termed as chorionic villi and sends the cells to the laboratory for testing. The samples are collected by using two methods. These methods are based on the location of the placenta.
Transabdominal: In this method, a long thin needle is inserted through the abdomen in your placenta. Then the needle collects a sample of tissue and then it is taken out. This is same as amniocentesis.
Transcervical: In this procedure a thin catheter is inserted into the cervix through placenta. The cells are taken into the catheter. This is a most common method of chorionic villus sampling.
CVS gives faster results when compared to amniocentesis.
Main reasons for having chronic villus sampling:
- If your age is 35 years or more
- If there are any abnormal ultrasound findings or there is any rise in nuchal translucency.
- If there is a family history of genetic disorders
- If abnormal first trimester screen results are found
Possible risks and side effects of CVS to you and your baby:
CVS is considered as an invasive diagnostic procedure that can cause various risks. The main risk due to CVS is miscarriage. But this is a very rare case, only 1 in 100 tests can result in miscarriage.
Chronic villus sampling is not suggested for women who:
- Are carrying multiples
- Are having active infections like STDs
- Have a history of vaginal bleeding in your pregnancy
- Have fibroids in the uterus
- Have uterus in tilted position which impedes the catheter
You will also experience side effects like:
- Pain at acupuncture points
It is better to consult your healthcare provider if the symptoms get worse. Also, consult the doctor if you have leakage of amniotic fluid, chills, rupture of fetal membranes, and fever.
So, before going to undergo this test, it is better to consult your doctor to know about the benefits and risks associated with CVS. Your doctor will decide, whether the test is suitable for you or not.