What is chorionic villus sampling?
Parents worried about their unborn baby’s chromosomal or genetic makeup may ask their doctor about chorionic villus sampling (CVS). This highly accurate (98%) procedure allows high-risk OBs to assess chromosomal abnormalities and genetic problems.
The CVS test for pregnancy is a test that involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and other genetic problems. If the patient does decide to terminate the pregnancy after getting abnormal CVS test results, it is safer than acting later in the pregnancy.
High-risk mothers in the Los Angeles area seek out the compassionate counsel of Dr. Rad, a double-board certified Obstetrician-Gynecologist with sub-specialty training in Maternal-Fetal Medicine (MFM).
Dr. Rad and his team at the Los Angeles Fetal and Maternal Care Center have decades of perinatology experience. They are among the very best high-risk pregnancy specialists in Los Angeles. The team is also available to provide expert second opinions concerning prenatal challenges.
Why is chorionic villus sampling done?
Higher risk expectant mothers who may benefit from undergoing chorionic villus sampling. The doctor may recommend CVS if:
- The first-trimester screen or prenatal cell-free DNA screen is positive.
- A previous pregnancy was affected by Down syndrome or another genetic disorder.
- The mother is over 35.
- There is a family history of a genetic condition.
- Either parent has a congenital disease.
- Risk of sex-linked genetic disease
What is Chorionic Villus Sampling and how does it work?
The placenta plays a major role in the baby’s development. In addition to providing oxygen and nutrients, it helps remove waste from the baby’s blood. The chorionic villi are thin projections of placental tissue that share the baby’s genetic makeup.
CVS, a prenatal test that samples the chorionic villi, can be performed as early as 10 weeks of pregnancy. The sample can be taken through the cervix (transcervical CVS) or the abdominal wall (transabdominal CVS).
Pregnant women with twins or other multiple pregnancies need a sample from each placenta to study the babies.
During CVS, either a narrow tube is guided through the cervix or a needle is inserted into the uterus to remove a tissue sample of chorionic villus cells from the placenta. The chorionic villi contain a baby’s genetic information which can be used to identify hundreds of genetic abnormalities, including:
Most women don’t find the procedure painful, but there may be some cramping or minor discomfort. The mother receives a follow-up ultrasound two to four days after the procedure to ensure their pregnancy is proceeding normally.
The doctor will discuss any troubling results with the parents.
What happens if a condition is identified?
It is a huge benefit to have a working relationship with a maternal-fetal medicine expert such as Dr. Rad. Even before they are completely verified, positive results can throw parents into turmoil.
Dr. Rad will clearly explain detailed information about the fetus’s condition. This includes talking about possible symptoms, treatment, support the baby may need, and if their life expectancy will be affected. A baby born with a condition affecting their chromosomes will always have the disease. Dr. Rad and his team will lay out the long-term options facing the parents.
CVS: understanding positive results
Parents mustn’t view the CVS results as that of a diagnostic test. The first step taken with positive results is to take an amniocentesis to confirm the diagnosis.
If the CVS results are confirmed, the parents have two options. This is a deeply personal and emotional decision and there is no “right” answer. Our team will do all we can to make sure you’re making a fully informed decision.
The patient’s options are:
- Continue with the pregnancy. Take the remainder of the pregnancy to find out everything about the condition and begin making any necessary changes to keep the baby safe.
- End the pregnancy. Ending a pregnancy involves undergoing an abortion. Pregnancy tissue, products of conception, the fetus, and the placenta are removed from the uterus.
Villus sampling risks
The CVS procedure is not risk-free. Your health care provider will discuss negative possibilities before administering the test such as:
- There is a 0.22% chance of miscarriage.
- The baby’s blood cells may enter the mother’s bloodstream, causing RH negative sensitization, and damaging the baby’s red blood cells.
- The test may cause an infection
- Preterm labor
- Limb defects
- Amniotic fluid leakage
Chorionic villus sampling vs amniocentesis
If the CVS results are troubling, the doctor may order an amniocentesis. This is a screen test during which a sample of amniotic fluid is withdrawn. The fluid is examined for genetic abnormalities or potential birthing complications.
Unlike CVS, amniocentesis cannot be performed until after the 15th week of gestation. There are valid reasons to take each test. Psychologically, CVS may be better because it allows the mother to process abnormalities earlier in the pregnancy.
The main advantage of using CVS is that genetic abnormalities can be discovered during the first trimester of pregnancy. However, the risks of CVS are higher than amniocentesis risks and CVS is unable to identify certain problems. These are:
Amniocentesis is also recommended if either parent was born with a neural tube defect, has already given birth to a baby with a neural tube defect, or received abnormal results from prenatal blood tests.
CVS and amniocentesis: what’s the difference?
The tests have some similarities, both:
- Can detect abnormalities in the developing fetus.
- Are given by inserting a thin needle into the placenta.
- Carry the increased risk of miscarriage.
- Are primarily given to women over 35.
The biggest difference is when the test is performed (CVS during the first trimester, amniocentesis at 15 or 16 weeks of gestational age) and what they test for. CVS is an internal test while amniocentesis is a genetic test.
If you have concerns about your pregnancy, consult with your maternal-fetal medicine expert earlier rather than later. Your doctor can go over the pros and cons of each test and help pick the best option for your pregnancy
About Dr. Rad and the Los Angeles Fetal and Maternal Care Center
The OB/GYN team at Los Angeles Fetal and Maternal Care is highly trained in high-risk pregnancies. In addition to displaying superior medical knowledge, the physicians and staff at the office display compassion and understanding when guiding patients down their complicated birthing path.
Dr. Rad has undergone rigorous training with high honors at prestigious, renowned institutions such as the David Geffen School of Medicine at UCLA, USC, Cedars-Sinai Medical Center, and UCSF Medical Center, as well as internationally in London, Austria, Israel, and Africa.
Call us at (844) 473-6100 or schedule your consultation online. We are currently accepting new patients.
We are conveniently located for patients throughout Southern California and the Los Angeles area at locations in or near Beverly Hills, Santa Monica, West Los Angeles, West Hollywood, Culver City, Hollywood, Venice, Marina del Rey, Malibu, Manhattan Beach, Newport Beach, Irvine, and Downtown Los Angeles. We also offer in-home prenatal care and a fly-in program for out-of-town and international patients. Dr. Rad even travels to patients who need him throughout the U.S. and around the world.
If you can’t make it to Dr. Rad, he also offers virtual consultations worldwide.