Chorionic Villus Sampling During Pregnancy - Risks and Benefits

Chorionic Villus Sampling - Procedure, Risks, Benefits, Timing, Weeks, Needle, Cost & Results

Chorionic Villus Sampling is a prenatal test that is used to detect birth defects, genetic problems such as Sickle Cell Anaemia or Cystic Fibrosis, Chromosomal problems such as Down syndrome, and many other problems during pregnancy. But it can't detect the neural tube defects such as Spina Bifida. In this test, Chorionic Villi (A small sample of cells) is taken from the tissue of the placenta where it attaches to the wall of the uterus. 

Chorionic Villus Sampling During Pregnancy - Risks and Benefits

Chorionic Villus Sampling definition

Chorionic Villi Have the same genes as the baby/fetus because they are the tiny parts of the placenta that are formed by the fertilized egg. Your doctor will suggest CVS if you have risk factors of having a baby with any genetic disease or any birth defect. By this test, these types of defects will be detected early in pregnancy. CVS can also identify the sex of the fetus so it is also able to detect the disorders that are linked to one sex. 

Chorionic Villus Sampling procedure

It requires genetic counseling which includes a detailed discussion about CVS procedure regarding its benefits, risks. After that, an ultrasound scan will be done to confirm the gestational stage of the fetus and the placenta's location. This scan is done to find out the appropriate time to perform the CVS procedure. CVS procedure is usually performed between 10 to 13 weeks of pregnancy. The Chorionic Villi sample is collected and then sent to a lab. In the lab, these cells are grown in a special fluid and then these cells are tested a few days later. The results of the Chorionic Villus Sampling procedure will be available within two weeks.

Ways of collecting Chorionic Villi

There are the following two ways by which Chorionic Villi is collected from the placenta of a pregnant woman :

Transabdominal CVS (Through the Abdomen of a pregnant woman)

Your belly is cleaned with an antiseptic and after that, a local anesthetic injection is used to numb it. A  needle is used to collect the Chorionic Villi through the abdomen of a pregnant woman. A needle is inserted into your womb through your abdomen's skin and guided towards the placenta by using images on the ultrasound scan. A syringe is attached with this needle to take a small sample of cells. After removing the sample the needle is removed. 

Transcervical CVS (Through Cervix of a pregnant woman)

In Transcervical CVS a thin plastic tube attached to the small forceps or syringe are inserted through the vagina and cervix of a pregnant woman. This tube is guided towards the placenta by using ultrasound images and a small sample of cells is removed from the placenta. 

(Also read: Is NST painful?)

Is CVS painful?

CVS is usually painless. Most of the women described it as being uncomfortable. 

Diseases which are identified by CVS

CVS (Chorionic Villus Sampling) helps in detecting the following diseases during early pregnancy :

  • Genetic disorder - Tay-Sachs Disease, Sickle Cell Anaemia and Cystic Fibrosis
  • Chromosomal Diseases - Down Syndrome, Edward's Syndrome
  • Birth Defects
  • Sex Disorders such as Muscular Dystrophy

Chorionic Villus Sampling risks

  • Although CVS is very safe there is a small risk of miscarriage after this procedure. 
  • The procedure of CVS is done in early pregnancy so it may carry a risk of miscarriage.
  • In some rare cases, this procedure may trigger a uterine infection. 
  • Rh Sensitization
  • In some rare cases when CVS procedure is done before nine weeks, limb defects in infants have been reported.
  • Cramping and Bleeding
  • Infection
  • Leaking of Amniotic Fluid.

Chorionic Villus Sampling benefits

CVS is done early in pregnancy and its results are obtained within 12 -14 days. So, CVS allows a pregnant woman to make choices about her pregnancy in the early stage of pregnancy. If a pregnant woman finds out any positive abnormalities test then she can choose to end her pregnancy in the beginning stage of her pregnancy. CVS is done earlier than Amniocentesis. 

Who needs to do a Chorionic Villus Sampling (CVS) test?

This test is suggested by the doctor if :

  • The age of the pregnant woman is 35 or more than 35 in their due date.
  • The couples who have a family history of a genetic condition.
  • The couples who already have a child with a genetic condition or any major birth defect.
  • A recent ultrasound found any abnormality.
  • A pregnant woman or her partner are carriers of any genetic condition. 

What happens after CVS?

  • After undergoing a CVS procedure you'll need to take rest for the whole day.
  • Your doctor will suggest you avoid sex, exercise, and any strenuous physical activities for three days following the procedure. 
  • Mild cramping and light bleeding are normal after the CVS procedure. Light Bleeding which is known as Spotting which lasts for a day or two is normal after this procedure. 

After CVS procedure

Call your doctor immediately if you notice any of the following symptoms after the CVS procedure :
  • Severe Cramping
  • Heavy Vaginal Bleeding
  • Fluid leakage from the vagina.
  • Shivering 
  • Fever
  • Uterine Contractions

Chorionic Villus Sampling timing

To perform a Chorionic Villus Sampling test 10 weeks is the earliest time which is recommended by the doctor. This test takes place in less than half an hour. It takes around 20-25 minutes. After this test, you'll be monitored for up to an hour to find out any side effects of the procedure. Then you can go home and take the rest. 

(Also read: Pregnancy at 8 weeks)

Chorionic Villus Sampling weeks

Chorionic Villus Sampling test is usually performed between 10 to 13 weeks of pregnancy (10 to 13 weeks after the last menstrual period 'LMP' of a pregnant woman).

Chorionic Villus Sampling needle

A needle is used to collect the cells from the abdomen of a pregnant woman to detect ant genetic disorders or chromosomal problems. Chorionic Villus Sampling needle set consists of a sample needle, guide needle, and a stylet.

Chorionic Villus Sampling cost

It depends on where you get it or whether you have insurance. It may costs you around $1300 to $7000.

Chorionic Villus Sampling results

The first results of Chorionic Villus Sampling (CVS) will be available within 3 days which will detect whether any chromosomal abnormalities have been found. If rarer conditions are also tested than the results should be available within 2 to 3 weeks.

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Disclaimer: This content is intended for general information only and it should not be used as the basis of patient treatment. The given content is not intended to be a substitute for professional medical advice, treatment, or any diagnosis. Always consult a doctor for more information. Our website doesn't claim responsibility for this information.

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