Prenatal Diagnosis Chorionic Villus Sampling (CVS) Versus Amniocentesis

Prenatal Diagnosis : Chorionic Villus Sampling (CVS) Versus Amniocentesis

Welcome to this article on Prenatal Diagnosis : Chorionic Villus Sampling(CVS) Versus Amniocentesis.

Being a parent means you never stop worrying, and that worry starts as soon as you know you’re expecting. Some worries are not really worries but curiosity, like what sex will the baby be and what will he or she look like.

Another major concern that keep most expecting mums up at night is whether or not their baby will be healthy?

In the past, you had to wait for birth to find out. But with the advent of advanced prenatal diagnosis and testing techniques like Chorionic Villus Sampling (CVS) and Amniocentesis, you no longer have to wait till birth to find out whether your baby is healthy or not .

These tests screens for a wide range of diseases and genetic disorders such as Sickle Cell Disease, Down syndrome.

They could also be used for paternity testing.

Let us now take a deeper look at Chorionic Villus Sampling (CVS) and Amniocentesis.

Chorionic Villus Sampling (CVS)

chorionic villus sampling

Chorionic Villus Sampling is normally performed in the first trimester, between the 10th and 12th week of pregnancy.

Using an ultrasound as a guide, the health care provider inserts a long, thin tube into the vagina and through the cervix and removes a small amount of chorionic villus from the outside of the sac where the baby develops. Local anesthesia is used for this test to reduce pain and discomfort.

Most women feel fine after the test, although some may have mild bleeding (spotting) afterward. Unfortunately, this procedure has a slightly higher risk of miscarriage than amniocentesis of about 1%-3% (1-3 cases out of 100).



Amniocentesis is normally performed in the second trimester, between the 15th and the 19th week of pregnancy.

Using an ultrasound as a guide, the health care provider inserts a long needle into the abdomen of the mother and draws out a small amount of amniotic fluid. Your body will make more fluid to replace the fluid that is taken out.

The baby will not be hurt during the procedure. Some women feel mild cramping during or after the procedure. Your doctor may tell you to rest on the day of the test, but usually you can resume normal activity the next day.

This test is more than 99% accurate in diagnosing chromosomal disorders like Down syndrome and Edward’s syndrome. Unfortunately, there is a small risk of miscarriage of about 0.5%-1% (1 or 2 cases out of 200).

For most parents, the decision to have these prenatal screening is not just straightforward, although the testing process is fairly clear-cut. This is because there are some pros and cons that must be weighed before making a decision.

Here are a few of the most common pros and cons of prenatal diagnosis:

Prenatal Diagnosis Pros:

  • Having foreknowledge of any problems can allow parents to prepare for caring for the child.
  • Advanced early knowledge may lead the parent to terminate the pregnancy. should they choose to.
  • In case any emergency treatment should be needed, parents would be at an advantage by having advanced knowledge of certain disorders.
  • Knowledge of any disorders prior to birth can give parents time to find specialists.
  • Genetic testing may identify a problem that can be rectified before birth.
  • Testing may be an advantage in that doctors may choose a delivery method that minimizes risk to the mother and infant.

Prenatal Diagnosis Cons:

  • Chorionic Villus Sampling (CVS) and amniocentesis carry some risk of miscarriage.
  • Testing may not be as precise as many parents believe them to be. Even for the problems that have been specifically tested, there is no guarantee that they don’t exist.
  • Tests may indicate a problem where none exist or may not detect a problem, giving false security.
  • Not all diseases or disorders are covered by testing. Many diseases have numerous complex forms that cannot all be covered in a generalized test.

Although prenatal diagnosis and testing is routine, it is an issue that is tricky and a matter of debate among many members of the disability community and parents alike.

It involves deeply felt beliefs toward abortion, the beginning of life, faith, fate, disability, social responsibility and quality of life issues.

Deciding to do any prenatal screening is a personal decision. It’s the beginning of many decisions you’ll have to make for you and your baby.

If you decide to do nothing, that’s fine, too. No matter what, get good prenatal care, eat healthy, and enjoy your pregnancy.

However, if you decide to do prenatal screening, here is a breakdown of what you should consider:

  • How early do you need to know? CVS is earlier.
  • Do you need to know about neural tube defects? Amniocentesis is the only one that can tell you.
  • Are you worried at all about missing limbs? CVS does have that risk.

Nisa Hospital is fully equipped to carry out these prenatal diagnosis tests.

We offer Chorionic Villus Sampling (CVS) and Amniocentesis screening, as well as other prenatal testing services like Harmony Test, NT Scan, Anomaly scan etc.

Visit our prenatal & maternity section to read more about our services