Ultrasonic guidance for chorionic villus sampling, imaging supervision and interpretation
CPT4 code
Name of the Procedure:
Ultrasonic Guidance for Chorionic Villus Sampling (CVS), Imaging Supervision and Interpretation
Summary
Chorionic Villus Sampling (CVS) is a prenatal test where a small sample of placental tissue is taken for genetic analysis. Ultrasonic guidance ensures the procedure is performed safely and accurately by providing real-time imaging of the uterus and placenta.
Purpose
The procedure helps diagnose certain genetic conditions and chromosomal abnormalities in the fetus, such as Down syndrome or cystic fibrosis. The goal is early detection of potential issues to inform parents and healthcare providers for better decision-making.
Indications
Indications for CVS include:
- Family history of genetic disorders
- Maternal age of 35 or older
- Abnormal ultrasound findings
- Positive results from other prenatal screenings
- Previous pregnancy with a chromosomal condition
Preparation
Patients are usually instructed to:
- Avoid eating or drinking for a few hours before the procedure, if sedation is planned.
- Inform the healthcare provider about any medications or allergies.
- Undergo a complete ultrasound assessment before the procedure.
Procedure Description
During the procedure:
- The patient lies on an exam table.
- An ultrasound transducer is used to visualize the uterus and placenta.
- Local anesthesia may be applied to the abdominal area.
- Under ultrasonic guidance, a thin needle or catheter is inserted through the abdomen or cervix to reach the placenta.
- A small tissue sample is extracted and sent to a lab for analysis.
The ultrasound is continually used to guide the placement of the needle and ensure the safety of both mother and fetus.
Duration
The procedure typically takes about 30 minutes, though the actual sampling process is usually completed in a few minutes.
Setting
CVS is generally performed in a hospital's prenatal diagnostic center or an outpatient clinic specializing in maternal-fetal medicine.
Personnel
The procedure is usually conducted by a maternal-fetal medicine specialist or an obstetrician, with assistance from a nurse and an ultrasound technician.
Risks and Complications
- Miscarriage (rare, approximately 1%)
- Infection
- Bleeding or spotting
- Rh sensitization (prevented with Rh immunoglobulin if needed)
Benefits
The primary benefit is early and accurate diagnosis of genetic conditions, allowing for informed decision-making and early intervention if necessary.
Recovery
Post-procedure care includes:
- Resting for the remainder of the day
- Avoiding strenuous activities for 1-2 days
- Monitoring for symptoms such as severe cramping, heavy bleeding, or fever
- Follow-up ultrasound check if any complications arise
Alternatives
- Amniocentesis: another prenatal diagnostic test usually performed at a later stage of pregnancy.
- Non-invasive prenatal testing (NIPT): a blood test from the mother that carries no risk of miscarriage but may be less definitive for some conditions.
- Wait for birth for diagnostic tests.
Patient Experience
During the procedure, the patient might feel mild discomfort or pressure but usually experiences minimal pain. Most discomfort can be managed with local anesthesia. Post-procedure, some cramping or light bleeding might occur but generally subsides within a day. Pain relievers like acetaminophen can be taken if needed.