Biopsy, Chorionic Villus
Biopsy, Chorionic Villus
SpecimenChorionic villus tissue.
This procedure is contraindicated for
- Patients with a history of or in the presence of incompetent cervix, vaginal infection, or Rh sensitization.
- Assist in the diagnosis of in utero metabolic disorders such as cystic fibrosis or other errors of lipid, carbohydrate, or amino acid metabolism
- Detect abnormalities in the fetus of women of advanced maternal age
- Determine fetal gender when the mother is a known carrier of a sex-linked abnormal gene that could be transmitted to male offspring, such as hemophilia or Duchenne’s muscular dystrophy
- Evaluate fetus in families with a history of genetic disorders, such as Down syndrome, Tay-Sachs disease, chromosome or enzyme anomalies, or inherited hemoglobinopathies
Abnormal karyotype: Numerous genetic disorders. Generally, the laboratory provides detailed interpretive information regarding the specific chromosome abnormality detected.
- Identification of abnormalities in chorionic villus tissue.
It is essential that critical findings be communicated immediately to the requesting health-care provider (HCP). A listing of these findings varies among facilities.
Timely notification of a critical finding for lab or diagnostic studies is a role expectation of the professional nurse. The notification processes will vary among facilities. Upon receipt of the critical finding the information should be read back to the caller to verify accuracy. Most policies require immediate notification of the primary HCP, hospitalist, or on-call HCP. Reported information includes the patient’s name, unique identifiers, critical finding, name of the person giving the report, and name of the person receiving the report. Documentation of notification should be made in the medical record with the name of the HCP notified, time and date of notification, and any orders received. Any delay in a timely report of a critical finding may require completion of a notification form with review by Risk Management.
- Failure to follow dietary restrictions before the procedure may cause the procedure to be canceled or repeated.
Nursing Implications and Procedure
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this procedure can assist in establishing a diagnosis of in utero genetic disorders.
- Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex or anesthetics.
- Obtain a history of the patient’s reproductive system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures. Include any family history of genetic disorders such as cystic fibrosis, Duchenne’s muscular dystrophy, hemophilia, sickle cell anemia, Tay-Sachs disease, thalassemia, and trisomy 21. Obtain maternal Rh type. If Rh-negative, check for prior sensitization.
- Record the date of the last menstrual period and determine that the pregnancy is in the first trimester between the 10th and 12th weeks.
- Obtain a history of intravenous drug use, high-risk sexual activity, or occupational exposure.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
- Review the procedure with the patient. Warn the patient that normal results do not guarantee a normal fetus. Assure the patient that precautions to avoid injury to the fetus will be taken by locating the fetus with ultrasound. Address concerns about pain related to the procedure. Explain that during the transabdominal procedure, any discomfort with a needle biopsy will be minimized with local anesthetics. Explain that during the transvaginal procedure, some cramping may be experienced as the catheter is guided through the cervix. Encourage relaxation and controlled breathing during the procedure to aid in reducing any mild discomfort. Inform the patient that specimen collection is performed by an HCP specializing in this procedure and usually takes approximately 10 to 15 min to complete.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Instruct the patient to drink a glass of water about 30 min prior to testing so that the bladder is full. This elevates the uterus higher in the pelvis. The patient should not void before the procedure.
- Make sure a written and informed consent has been signed prior to the procedure and before administering any medications.
- Potential complications:
Women at risk for or with known cervical abnormalities should be aware of the risks of miscarriage due to incompetent (loose) cervix (related to passing a catheter or other instrument through the cervix, weakening the cervix). Rh-negative women risk mixing of the maternal and fetal blood supply (related to the invasive nature of the procedure and potentially resulting in development of maternal antibodies directed against fetal blood cells; a situation that can develop into hemolytic disease of the newborn).
- Ensure that the patient has a full bladder before the procedure.
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Have emergency equipment readily available.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen containers with the corresponding patient demographics, initials of the person collecting the specimen, date and time of collection, and site location.
- Have the patient remove clothes below the waist. Transabdominal: Assist the patient into a supine position on the examination table with abdomen exposed. Drape the patient’s legs, leaving abdomen exposed. Transvaginal: Assist the patient into a lithotomy position on a gynecologic examination table (with feet in stirrups). Drape the patient’s legs. Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement during the local anesthetic and the procedure.
- Record maternal and fetal baseline vital signs, and continue to monitor throughout the procedure. Monitor for uterine contractions. Monitor fetal vital signs using ultrasound. Protocols may vary among facilities.
- After the administration of local anesthesia, use clippers to remove hair from the surgical site if appropriate, cleanse the site with an antiseptic solution, and drape the area with sterile towels.
- Assess the position of the amniotic fluid, fetus, and placenta using ultrasound.
- A needle is inserted through the abdomen into the uterus, avoiding contact with the fetus. A syringe is connected to the needle, and the specimen of chorionic villus cells is withdrawn from the uteroplacental area. Pressure is applied to the site for 3 to 5 min, and then a sterile pressure dressing is applied.
- Assess the position of the fetus and placenta using ultrasound.
- A speculum is inserted into the vagina and is opened to gently spread apart the vagina for inspection of the cervix. The cervix is cleansed with a swab of antiseptic solution.
- A catheter is inserted through the cervix into the uterus, avoiding contact with the fetus. A syringe is connected to the catheter, and the specimen of chorionic villus cells is withdrawn from the uteroplacental area.
- Monitor the patient for complications related to the procedure (e.g., premature labor, allergic reaction, anaphylaxis).
- Place tissue samples in formalin solution. Label the specimen, indicating site location, and promptly transport the specimen to the laboratory for processing and analysis.
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- After the procedure, the patient is placed in the left side-lying position, and both maternal and fetal vital signs are monitored for at least 30 min. Protocols may vary among facilities.
- Observe/assess for delayed allergic reactions, such as rash, urticaria, tachycardia, hyperpnea, hypertension, palpitations, nausea, or vomiting.
- Observe/assess the biopsy site for bleeding, inflammation, or hematoma formation.
- Instruct the patient in the care and assessment of the site.
- Instruct the patient to report any redness, edema, bleeding, or pain at the biopsy site.
- Advise the patient to expect mild cramping, leakage of small amount of amniotic fluid, and vaginal spotting for up to 2 days following the procedure. Instruct the patient to report moderate to severe abdominal pain or cramps, increased or prolonged leaking of amniotic fluid from vagina or abdominal needle site, vaginal bleeding that is heavier than spotting, and either chills or fever.
- Administer Rho(D) immune globulin (RhoGAM IM or Rhophylac IM or IV) to maternal Rh-negative patients to prevent maternal Rh sensitization should the fetus be Rh-positive.
- Administer mild analgesic and antibiotic therapy as ordered. Remind the patient of the importance of completing the entire course of antibiotic therapy, even if signs and symptoms disappear before completion of therapy.
- Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Encourage family to seek counseling if concerned with pregnancy termination or to seek genetic counseling if chromosomal abnormality is determined. Decisions regarding elective abortion should take place in the presence of both parents. Provide a nonjudgmental, nonthreatening atmosphere for a discussion during which risks of delivering a developmentally challenged infant are discussed with options (termination of pregnancy or adoption). It is also important to discuss problems the mother and father may experience (guilt, depression, anger) if fetal abnormalities are detected.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
- Instruct the patient in the use of any ordered medications. Explain the importance of adhering to the therapy regimen. As appropriate, instruct the patient in significant side effects and systemic reactions associated with the prescribed medication. Encourage her to review corresponding literature provided by a pharmacist.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. There are numerous tests for fetal genetic testing associated with inherited diseases and congenital abnormalities. The tests can be performed from chorionic villus sampling or amniotic fluid by methods that include polymerase chain reaction, microarray, and cell culture with karyotyping comparison. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Related tests include amniotic fluid analysis, and L/S ratio, chromosome analysis, α1 fetoprotein, HCG, hexosaminidase A and B, newborn screening, US biophysical profile, and US obstetric.
- Refer to the Reproductive System table at the end of the book for related tests by body system.