Chorionic Villus: Purpose & Procedure Insights

Parenting brings along a ton of added responsibilities on both parents. In some instances, parenthood is accompanied by a great deal of concern about the baby’s health. If you’re due soon, to begin with, know that your concern is entirely valid as the mother. It is your right to know every tiny detail about your would-be child before you deliver your child.

This is where Chorionic Villus Sampling comes into the picture.

For instance Anisha, a 37-years-old lawyer by profession who was expecting her first child after a sad miscarriage four years ago. As a corporate employee, Anisha had been working long hours daily. She came from a family where many members were carriers of the sickle cell trait, including Anisha. This means although none of them had it, there were high chances the baby could suffer from sickle cell anaemia as her husband was also a carrier of the condition. As the concern grew day by day, she and her husband finally visited a doctor to get rid of the anxiety. The gynaecologist presented them with two options: Amniocentesis and Chorionic Villus sampling from the placenta. 

What Is a Chorionic Villus?

The chorionic villi (singular: villus) are small extensions of placental tissue. They arise from the trophoblast layer, which matures into a zygote after successful implantation occurs. It resembles fingers and contains the same genetic material as the foetus. You can use them to determine any genetic or chromosomal disorders that the newborn can suffer from. 

Depending on the family history and the availability of lab testing at the treatment, you can do testing for various genetic abnormalities and conditions here. This process has been instrumental in preventing couples from having children with incurable genetic disorders like down syndrome. 

As for amniocentesis, this test can also result in a miscarriage, but you’ll be further along in your pregnancy before you recieved news of the findings, giving you less time to weigh your options. Thus  Anisha chose Chorionic Villi Sampling to find that her baby was not affected with sickle cell anaemia but was a carrier just like her parents.

Let us discuss the steps of going through this test mentioned above so that you know what your doctor is talking about when he prescribes it to you.

Purpose of CVS

1. A prenatal screening test came back positive for you: 

Suppose the screening test results, such as a first-trimester screen or a prenatal cell-free DNA screening, are positive or concerning. In that case, Doctors may use Chorionic Villus collection to confirm or rule out a diagnosis.

2. You had a chromosomal disorder previously, during another conception:

This pregnancy might be at a slightly higher risk if a pregnancy prior was impacted by Down syndrome or another chromosomal disorder.

3. You’re at least 35 years old:

Babies born to mothers who are 35 or older are more likely to have Down syndrome and other genetic abnormalities.

4. You or your spouse have a hereditary illness in the family:

You or your partner have been identified as a known carrier of a genetic disorder. Chorionic Villus Sampling can be used to diagnose a variety of genetic disorders, including Tay-Sachs disease and cystic fibrosis, in addition to Down syndrome.

Procedure of Chorionic Villus Sampling?

The placenta has tiny finger-like structures called chorionic villi (which provides nutrients from the mother to the foetus through the umbilical cord). They share the fetus’s chromosomes and genetic composition.

Some chorionic villi cells are extracted and analysed for chromosomal abnormalities such as Down’s syndrome, Tay-Sachs disease, and fragile X syndrome during a CVS.

There are two ways to do this test:

1. Transcervical: A tiny tube is inserted from the vaginal canal into the cervix using ultrasound as a guide. A sample of tissue is removed from the chorionic villi using gentle suction.
2. Transabdominal: Under ultrasound guidance, a needle is introduced through the abdominal wall, and a sample of the chorionic villi is removed. Anisha went for this method.

CVS is said to be painless as per some ladies. However, while the sample is being obtained, others experience cramping comparable to period cramps. The doctor may examine the fetus’ heart rate after taking the sample. After the test, you should rest for several hours. As for Anisha, it was painless.

Side Effects of CVS

Following are some of the possible side effects of this test:

• There’s a 1% chance of miscarriage (the risk is higher with the transcervical method than with the transabdominal approach)
• Spots of infection or bleeding (this is more common with the transcervical method)
• When a test is performed too early in pregnancy, it can result in birth abnormalities.

When Is Chorionic Villus Sampling Done?

CVS is performed at 10 to 13 weeks. Anisha went during her 11th week, so it was riskless.

When to Expect CVS Results?

Depending on what the test is looking for, results are usually available from a few hours to a few days.

We hope this puts your mind at ease if you have a CVS scheduled in the near future.