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Pregnancy is filled with excitement, anticipation, and many important decisions. Along with preparing for a growing family, many parents want reassurance about their baby’s health as early as possible. While routine prenatal care provides valuable information, some pregnancies may benefit from additional genetic testing to better understand a baby’s development before birth.

Chorionic Villus Sampling (CVS) is one of the earliest diagnostic tests available during pregnancy. Unlike screening tests that estimate the chance of a condition being present, CVS can provide a definitive diagnosis for many genetic and chromosomal disorders. Receiving accurate information early gives families more time to understand their options, plan future care, and work closely with their healthcare team.

Although the idea of prenatal testing may seem overwhelming, understanding how CVS works can make the process much less intimidating. Learning when the test is recommended, what happens during the procedure, and what the results can reveal helps parents feel more informed and confident. With guidance from experienced maternal-fetal medicine specialists and genetic counselors, families can make decisions that align with their medical needs and personal values.

What Is Chorionic Villus Sampling (CVS)?

Chorionic Villus Sampling, commonly known as CVS, is a prenatal diagnostic procedure performed during the first trimester, usually between the 10th and 13th weeks of pregnancy. The test involves collecting a very small sample of chorionic villi, which are tiny finger-like structures found in the placenta. Because these cells contain the same genetic material as the developing baby, they can be analyzed for a wide range of inherited and chromosomal conditions.

Unlike prenatal screening tests, which estimate the likelihood of a condition, CVS provides highly accurate diagnostic results for many genetic disorders. It can identify chromosomal abnormalities such as Down syndrome (Trisomy 21), Trisomy 18, and Trisomy 13. The test can also diagnose many inherited conditions when there is a known family history or when parents are known carriers of specific genetic disorders.

One of the greatest advantages of CVS is timing. Since it is performed earlier than amniocentesis, families receive important information during the first trimester, allowing additional time for medical planning and counseling if needed.

Who May Benefit From CVS Testing?

CVS is not recommended for every pregnancy, but it may be appropriate when certain risk factors are present. Your healthcare provider will review your medical history, family history, and prenatal screening results before discussing whether the procedure is suitable for you.

Women may be candidates for CVS if they:

• Receive abnormal results from first-trimester prenatal screening
• Have a family history of inherited genetic disorders
• Previously had a pregnancy affected by a chromosomal condition
• Are known carriers of specific genetic diseases
• Have a partner who is a carrier of an inherited condition
• Need early diagnostic information because of increased pregnancy risk

Advanced maternal age alone does not automatically mean CVS is necessary, but it may be considered alongside other screening results and individual circumstances.

Meeting with a genetic counselor before testing helps families understand both the benefits and limitations of the procedure, making it easier to make informed decisions.

What Happens During the CVS Procedure?

The CVS procedure is generally completed in less than 30 minutes and is performed using continuous ultrasound guidance to monitor the pregnancy throughout the process.

Depending on the position of the placenta, the physician may collect the sample using one of two methods:

Transcervical CVS

A thin catheter is gently inserted through the cervix to obtain a small placental tissue sample.

Transabdominal CVS

A thin needle passes through the abdomen into the placenta while ultrasound helps guide its placement safely.

Many patients describe the procedure as uncomfortable rather than painful. Some experience mild cramping or light spotting afterward, which often resolves within a short period. Healthcare providers usually recommend taking it easy for the remainder of the day before returning to normal activities based on individual recommendations.

The medical team carefully monitors both the mother and baby before, during, and after the procedure to support a safe experience.

What Can CVS Detect?

CVS provides detailed genetic information that cannot be obtained through routine ultrasound examinations alone. Laboratory specialists analyze the placental cells to identify chromosomal or genetic abnormalities.

The test may diagnose conditions including:

• Down syndrome (Trisomy 21)
• Edwards syndrome (Trisomy 18)
• Patau syndrome (Trisomy 13)
• Cystic fibrosis
• Tay-Sachs disease
• Sickle cell disease
• Certain muscular dystrophies
• Many other inherited genetic disorders

It is important to understand that CVS does not detect every possible birth defect. For example, neural tube defects such as spina bifida are not identified through CVS. Because of this, additional prenatal screening and ultrasound examinations remain important throughout pregnancy.

Your healthcare provider will explain which conditions are included based on your personal medical history and any specialized laboratory testing being performed.

Understanding the Benefits and Risks

Like every medical procedure, CVS offers significant benefits while also carrying certain risks that should be carefully discussed beforehand.

Benefits

The primary benefit is receiving reliable diagnostic information during the first trimester. Early results allow parents to:

• Better understand their baby’s condition
• Prepare emotionally and medically
• Coordinate care with appropriate specialists
• Plan for delivery if specialized newborn care will be needed
• Consider all available options with adequate time

Having answers early can reduce uncertainty and support informed decision-making throughout pregnancy.

Risks

Although CVS is considered safe when performed by experienced specialists, there are small risks involved, including:

• Miscarriage
• Infection
• Bleeding
• Cramping
• Rare complications related to the procedure

Your physician will carefully explain these risks in the context of your individual pregnancy before recommending the procedure.

What Happens After Receiving the Results?

Waiting for test results can be emotionally challenging. Depending on the type of laboratory analysis performed, some preliminary findings may become available within a few days, while complete genetic testing may take one to two weeks.

If results are normal, families often experience reassurance while continuing routine prenatal care. If a genetic condition is identified, your healthcare team will discuss the diagnosis thoroughly and explain the next steps.

Additional consultations may include:

• Maternal-fetal medicine specialists
• Genetic counselors
• Pediatric specialists
• Neonatologists
• Other healthcare professionals depending on the diagnosis

These discussions provide families with clear medical information, expected outcomes, available treatments, and support resources. Every pregnancy is unique, and decisions following diagnostic testing are highly personal. Compassionate counseling ensures parents receive accurate information without pressure while respecting their individual beliefs and goals.

Conclusion

Choosing whether to undergo CVS testing is a personal decision that depends on your medical history, family history, and pregnancy circumstances. For families who qualify, this first-trimester diagnostic test can provide reliable genetic information earlier than many other prenatal diagnostic options, offering valuable time for planning, counseling, and ongoing medical care. Understanding how the procedure works, what it can diagnose, and what to expect afterward helps reduce uncertainty and allows parents to make informed decisions with confidence. If you have questions about whether CVS testing is appropriate for your pregnancy, the experienced specialists at Greater Washington Maternal-Fetal Medicine and Genetics can provide personalized guidance, compassionate counseling, and comprehensive prenatal care to help you make the best decision for your growing family. Contact us today to schedule a consultation.