CVS Test in Chennai – Early Diagnostic Prenatal Testing
Accurate first-trimester diagnostic testing to detect chromosomal and genetic abnormalities, performed under continuous ultrasound guidance by FMF-certified fetal medicine specialist Dr. Deepthi Jammi at Jammi Scans, Chennai.
What Is CVS (Chorionic Villus Sampling)?
Chorionic Villus Sampling (CVS) is a diagnostic prenatal test used to confirm whether the baby has certain chromosomal or genetic conditions.
CVS involves collecting chorionic villi cells (tiny finger-like projections in the placenta) which contain crucial information about the baby's genetic material.
During the CVS procedure, a small sample of placental tissue is carefully collected and sent to the laboratory for detailed analysis.
CVS is a diagnostic test, meaning it can confirm whether the baby has a specific chromosomal or genetic condition. A positive result indicates that the baby has the tested condition, while a negative result indicates that the baby does not have the condition.
Chorionic Villus Sampling Procedure 
Chorionic Villi in the placenta When Is the CVS Test Done During Pregnancy?
Ideally, the CVS test is carried out between 11 weeks and 13 weeks + 6 days of pregnancy.
Placenta fully formed – By 11 weeks of pregnancy, the placenta is sufficiently developed for safe sampling.
Early diagnosis possible – Helps detect chromosomal or genetic conditions in the first trimester.
Timely decisions possible – Allows parents and doctors to plan further treatment or care earlier in pregnancy.
When Is CVS Recommended?
While CVS is not routinely recommended for all pregnant women, it is an important test when there is an increased risk of a chromosomal or genetic condition. Your doctor may recommend a CVS test if:
NT scan results are abnormal
Double marker test results are abnormal
Structural abnormalities are detected on ultrasound
Previous child or pregnancy affected by Trisomy 21, 13, or 18
Screening tests show high risk
Maternal age is 35 years or above
Family history of genetic disorders
Parents are known carriers of genetic disease
What Conditions Can CVS Detect?
Chorionic Villus Sampling (CVS) is a highly accurate diagnostic test used to identify a wide range of chromosomal and genetic conditions early in pregnancy.
🧬 Chromosomal Abnormalities
- ✓Down syndrome (Trisomy 21): Extra copy of chromosome 21
- ✓Edwards syndrome (Trisomy 18): Extra copy of chromosome 18
- ✓Patau syndrome (Trisomy 13): Extra copy of chromosome 13
- ✓Turner syndrome (Monosomy X): Missing or altered X chromosome
- ✓Other sex chromosome abnormalities
- ✓Rare aneuploidies (extra or missing chromosomes)
🩸 Genetic Disorders
- ✓Thalassemia
- ✓Sickle cell disease
- ✓Cystic fibrosis
- ✓Muscular dystrophy
- ✓Tay-Sachs disease
Important Note: CVS cannot detect neural tube defects such as spina bifida. Therefore, a second-trimester scan or blood test (like checking AFP levels) is required to screen for neural tube defects.
How Is CVS Performed?
Chorionic Villus Sampling is a safe, outpatient procedure performed by our fetal medicine experts under continuous ultrasound guidance.
Before the Procedure
- A detailed ultrasound scan is performed to determine the baby's position and placental location.
- The safest route (transabdominal or transcervical) is decided based on the placental position.
- The healthcare provider explains the procedure, possible risks, and obtains informed consent.
During the Procedure
- The abdomen or cervix area is cleaned with an antiseptic solution.
- Under continuous ultrasound guidance, a thin needle or catheter is carefully guided to the placenta.
- A small sample of chorionic villi tissue is collected.
- The sample is immediately sent to the laboratory for genetic testing.
After the Procedure
- The baby's heartbeat and overall wellbeing are checked using ultrasound.
- The mother is usually kept under observation in the clinic for about an hour.
- The mother is advised to take rest and avoid strenuous physical activity for the rest of the day.
CVS Test Report
See what a comprehensive CVS test reports look like.
Is CVS Painful?
As CVS is an interventional procedure, it may cause mild discomfort but is usually very well tolerated by most expectant mothers.
What Is the Risk of Miscarriage?
Understanding the safety profile of the CVS procedure.
The general miscarriage risk after CVS is estimated to be about 1 in 100 to 1 in 200.
Most procedure-related losses, if they occur, happen within the first 72 hours after the procedure, although they may occur later in rare cases.
It is important to seek immediate medical attention if you experience:
- Heavy bleeding
- Severe abdominal cramps
- Leakage of fluid
- Fever
When Will I Get the Results?
CVS test results usually take about 2 to 3 weeks, although this may vary depending on the specific type of genetic testing performed and the laboratory processing your sample.
FAQs
Quick answers to your most common questions.
CVS has an accuracy rate of about 99% for detecting chromosomal abnormalities. However, in rare cases, results may be unclear due to a condition called Confined Placental Mosaicism (CPM), where placental cells differ genetically from fetal cells.
- Both CVS and amniocentesis are diagnostic tests used to confirm genetic or chromosomal conditions in the baby.
- In amniocentesis, a sample of amniotic fluid is collected from the uterus for testing. In CVS, a small sample of placental tissue is collected.
- CVS is performed earlier in pregnancy, while amniocentesis is performed later and can also detect neural tube defects.
The main advantage of CVS is that it allows early diagnosis in the first trimester. This helps parents and doctors identify chromosomal or genetic conditions earlier in pregnancy and plan further care accordingly.
Both Amniocentesis and CVS carry a small risk of complications, typically around 0.5%–1%. When the procedure is performed by an experienced fetal medicine specialist under continuous ultrasound guidance, the risk of miscarriage is considered very low.
NIPT is a highly accurate screening test, but it cannot confirm a diagnosis. If NIPT shows a high-risk result, a diagnostic test such as CVS or amniocentesis is required to confirm whether the baby actually has the condition.
Limitations of CVS
While CVS is a highly accurate diagnostic test, it does have a few limitations:
CVS cannot detect neural tube defects such as spina bifida.
It cannot detect all structural abnormalities. It carries a small risk of miscarriage (0.5–1%).
In rare cases, the placental cells tested may have a different genetic makeup from the fetus.
This is known as Confined Placental Mosaicism (CPM) and may sometimes require further testing such as amniocentesis.
CVS can detect the presence of a genetic condition, but it cannot determine its severity
Important: Despite these limitations, the Anomaly scan remains one of the most valuable tools in prenatal assessment. At Jammi Scans, Dr. Deepthi Jammi uses advanced ultrasound technology and specialised expertise to provide the most accurate evaluation possible.
Amniocentesis Vs CVS
A detailed comparison to help you understand the key differences between Chorionic Villus Sampling and Amniocentesis.
| Factor | CVS (Chorionic Villus Sampling) | Amniocentesis |
|---|---|---|
| When it is done | 11–13 weeks + 6 days | 15–20 weeks |
| Trimester | 1st trimester | 2nd trimester |
| Sample collected | Placental tissue (chorionic villi) | Amniotic fluid |
| What it detects | Chromosomal and certain genetic conditions | Chromosomal, genetic conditions and neural tube defects |
| Neural tube defects | Cannot detect | Can detect (via AFP levels) |
| Result timing | 2–3 weeks | 2–3 weeks |
| Risk of miscarriage | Small risk (about 0.5–1%) | 0.5% |
| Accuracy | 99% | 99–99.4% |
| When is it usually recommended? | When early diagnosis is needed after abnormal screening (NT scan/NIPT) | When confirmation is needed in the second trimester or to check neural tube defects |
Why Choose Jammi Scans for Pregnancy Ultrasound?
Specialized care, advanced technology, and compassionate expertise — all focused on your pregnancy journey.
Jammi Scans
At Jammi Scans, all scans are performed by Dr. Deepthi Jammi, an expert Fetal Medicine Specialist, ensuring high standards of accuracy and care for anomaly scans in Chennai.
Reports within 15 mins
Accurate reports delivered the same day, with clear explanations to help parents understand every detail confidently.
Dr. Deepthi Jammi
Dr. Deepthi Jammi is an FMF-certified fetal medicine specialist (Fetal Medicine Foundation), and she ensures every single FMF protocol is followed to provide accurate results.
Accredited & Certified
Jammi Scans is NABCB-accredited and ISO 9001:2015 certified, meaning we follow the highest standards, undergo regular audits, and ensure that every scan is done precisely.
Pregnancy Ultrasound
Jammi Scans is dedicated exclusively to pregnancy ultrasound and fetal medicine.
Latest Technology
Jammi Scans employs the latest technology ultrasound machines such as the GE Voluson Expert 22 and combines it with Dr. Deepthi Jammi's expertise in fetal medicine to provide comprehensive results.
Pregnancy Ultrasound Scans We Offer
Comprehensive fetal screening at every stage — from confirmation to final growth assessment.
An early pregnancy scan is the first ultrasound scan done to confirm pregnancy. Check the viability of the baby.
- Check the viability of the baby
- Check the baby's position
- Count the number of babies
- Check the presence of fetal heart rate
- Estimate the baby's due date
First-trimester screening for chromosomal abnormalities using nuchal translucency (NT) and nasal bone (NB) assessment.
- Down syndrome risk screening
- Fetal nasal bone presence
- Nuchal translucency thickness
- Ductus venosus & tricuspid flow
A detailed anatomy scan is a comprehensive scan used to evaluate fetal development and detect structural anomalies.
- Brain, face, spine & limbs
- Heart (4-chamber view)
- Stomach, kidneys, bladder
- Placenta position & cord
A growth scan is a third-trimester ultrasound that monitors the baby's growth and development.
- Estimated fetal weight (EFW)
- Amniotic Fluid Index (AFI)
- Fetal position & movements
- Placental maturity
A fetal Doppler scan is used to assess blood flow between the mother, placenta, and baby.
- Umbilical artery PI/RI
- MCA Doppler for anemia risk
- Uterine artery notching
- Combined with Growth Scan
What Our Patients Say
Real reviews from mothers who trusted us with their pregnancy journey.
"Dr. Deepthi is so professional and does the scan clearly. The entire team out there are friendly and the center is maintained clean and neat. The process defines to get the scan done is also easy. Highly recommended for pregnancy scans"
"All the attenders and sisters are very kind. Well responsive. Patient in clarifying questions. Dr. Deepti ma'am is a positive vibe. She takes good time with each pregnant women and explain everything in detail."
"Best place for scan .. clear and accurate scan.. clean environment and good service.. Dr. Deepthi madam, was so kind in explaining the scanning process and fetal growth .. Her communication to patient was so good, clear and precise. One must visit this place. Highly recommended."
Jammi Scans – Pregnancy Ultrasound Centre, T. Nagar, Chennai
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