Chorinic Villous Sampling
What Is Chorionic Villus Sampling?
The placenta provides oxygen and nutrients to the growing baby during pregnancy and removes waste products from the baby’s blood. The chorionic villi are wispy projections of placental tissue that share the baby’s genetic makeup.
Chorionic villus sampling (CVS) is a prenatal test performed by collecting a sample of chorionic villus cells from the placenta to determine if an unborn child is at risk for chromosomal defects.Tiny finger-like projections on the placenta called the chorionic villi are taken and sent to the lab for genetic analysis.
The sample is taken through the abdominal wall (transabdominal). Chorionic villi can be analyzed to identify genetic and chromosomal abnormalities. Because the chorionic villi are of fetal origin, examining them can give a clear picture of the genetic makeup of the developing fetus. CVS is usually done between weeks 11 and 13 of pregnancy earlier than other prenatal diagnostic tests, such as amniocentesis (where the patient has to be at least 16 weeks pregnant).
Chorionic villus sampling (CVS) is a prenatal test performed by collecting a sample of chorionic villus cells from the placenta to determine if an unborn child is at risk for chromosomal defects.Tiny finger-like projections on the placenta called the chorionic villi are taken and sent to the lab for genetic analysis.
The sample is taken through the abdominal wall (transabdominal). Chorionic villi can be analyzed to identify genetic and chromosomal abnormalities. Because the chorionic villi are of fetal origin, examining them can give a clear picture of the genetic makeup of the developing fetus. CVS is usually done between weeks 11 and 13 of pregnancy earlier than other prenatal diagnostic tests, such as amniocentesis (where the patient has to be at least 16 weeks pregnant).
Best Choronic Villus Sampling in Salem
Mediplus scans and labs is one of the best places for Chronic villus sampling in Salem. We aim to provide all your pregnancy-related tests at top-notch quality and accuracy. Your test procedures are handled under the guidance of the Fetal Medicine specialist Dr Nivethitha Mediplus scans and labs who got trained under the pioneers of the fetal medicine field -Dr . Suresh S. , Dr. Indrani Suresh and Dr. Sudarshan Suresh.
When Is It Considered?
CVS is offered only if there’s a high risk that the fetus could have a genetic or chromosomal condition. This could be because:
- A pregnancy screening test has suggested there may be a problem, such as Down syndrome, Edward's syndrome or Patau syndrome.
- The mother has had a previous pregnancy with the above mentioned chromosomal problems.
- The patient has a family history of a genetic condition, such as thalassaemia, cystic fibrosis or muscular dystrophy,and/or an abnormality is detected in the baby during a routine ultrasound scan.
- The patient is over 37 years of age since women over 37 are at higher risk of having children with chromosomal abnormalities.
- The patient or her partner has a family history of a genetic disorder.
- The patient or her partner has a genetic disorder.
- The patient has other children with genetic or biochemical disorders.
It’s important to remember that the patient does not have to have CVS just because it’s recommended. It’s up to the patient to decide whether she wants it based on the information/counselling provided by the Fetal Medicine specialist.
The test can detect more than 200 different genetic and biochemical conditions. Performing the test early on during the pregnancy gives parents the information they need to cope with some of the complications of the pregnancy or the possibility of terminating the pregnancy.
The test can detect more than 200 different genetic and biochemical conditions. Performing the test early on during the pregnancy gives parents the information they need to cope with some of the complications of the pregnancy or the possibility of terminating the pregnancy.
How Is The Procedure Performed?
Before the procedure, the patient will have an ultrasound to confirm how far along the pregnancy is and make sure it’s possible to get a good sample for the test.
The amniotic sac where the baby is growing won’t be disturbed during the procedure. The procedure takes about 20 to 30 minutes from start to finish, and the extraction itself takes only a few minutes.
However, some patients may experience some pain or discomfort in the abdominal area.
Once the procedure is done, the doctor checks the baby’s heart rate, the patient’s BP along with breathing.
The amniotic sac where the baby is growing won’t be disturbed during the procedure. The procedure takes about 20 to 30 minutes from start to finish, and the extraction itself takes only a few minutes.
However, some patients may experience some pain or discomfort in the abdominal area.
Once the procedure is done, the doctor checks the baby’s heart rate, the patient’s BP along with breathing.
Factors To Consider When Deciding Between CVS And Amniocentesis?
Both tests can tell whether the baby has a chromosomal problem or certain genetic disorders. CVS is done earlier in pregnancy (usually between 11 and 13 weeks), so the doctor can find out sooner about the baby’s condition.
If there is a severe problem and the patient opts to terminate the pregnancy, she’ll be able to do so while still in the first trimester.
On the other hand, the patient may prefer to wait for the results from second-trimester screening before subjecting herself to an invasive test. At that point, amniocentesis would be the only option.
If there is a severe problem and the patient opts to terminate the pregnancy, she’ll be able to do so while still in the first trimester.
On the other hand, the patient may prefer to wait for the results from second-trimester screening before subjecting herself to an invasive test. At that point, amniocentesis would be the only option.
When Is CVS Not Recommended?
When the placental position is feasible to get the sample / the patient has an active infection/ the patient has experienced vaginal bleeding during Pregnancy
What Are The Risks Of CVS?
- Bleeding and cramping– The patient may experience cramping or bleeding. CVS may cause cramping, leakage of amniotic fluid and vaginal spotting. These will go away in 1 to 2 days.
- Infection - As with any invasive procedure, there is a risk of infection, though this complication occurs rarely.
- Rh sensitization – During the procedure, there’s a chance that the baby’s blood may be mixed with the mother’s blood. If the patient has Rh-negative blood and the father has Rh-positive blood, the baby has Rh-positive blood, the patient’s body could produce antibodies that attack the baby’s blood cells. If this occurs, the doctor can prescribe Rh immune globulin. This medication will stop the patient from becoming sensitized. If the patient is Rh-negative, the doctor must be informed.
- Accidental abortion or miscarriage – it’s estimated to be between one in 100 and one in 200
The patient should discuss the risks and benefits of the test with the obstetrician. Even though the doctor may recommend the test, the decision to undergo the procedure is entirely up to the patient and her family.
How accurate is a CVS test?
CVS has an accuracy rate of 98%. However, there are 1 to 2% chances of getting an unclear report. This is called confined placental mosaicism. Under this situation, the situation is confirmed with further testing.
What is the difference between amniocentesis and chronic villus sampling?
These two tests help screen the fetus for some genetic disorders, mainly Down’s syndrome. In amniocentesis, a sample of amniotic fluid is removed from your uterus (second trimester testing )for testing, while CVS removes a small sample of placenta tissue from the uterus (First trimester testing).
What is the advantage of Chronic villus sampling?
Chronic villus sampling gives a very accurate screening of genetic abnormalities and maybe the best option if you want to know to have genetic screening done in your first trimester.
Is CVS more accurate than NIPT?
NIPT is only a screening test which has a low false-positive rate of 1 in 1,000. However, if your advised to terminate the pregnancy after your NIPT results, it’s recommended to have a CVS or amniocentesis test performed to confirm the diagnosis.
