Chorionic villus sampling
Chorionic villus sampling (fig. 1), or CVS, is a prenatal test that can detect certain genetic abnormalities in the fetus. To perform the test, a physician uses a needle to collect cells from the placenta. These cells are then analyzed for genetic problems.  Figure 1 Prenatal testing is often a topic of concern for parents-to-be. It is important to remember that most tests are normal, and abnormal results may open opportunities for successful interventions or informed choices.CVS is not a routine test. It may be offered to pregnant women who have an increased risk of having a baby with a genetic birth defect that can be detected by CVS. These women include the following:
Early CVS, prior to 9 weeks, sometimes causes birth defects in the limbs, for example, missing fingers and toes, and sometimes malformations in the tongue and jaw. Most physicians agree that CVS should not be done before 10 weeks. CVS may be chosen as the method of prenatal testing for those unable to have an amniocentesis, and those who may consider a therapeutic abortion in the case of birth defects. If the fetus has serious complications, an earlier abortion is often easier and safer than a second trimester abortion or possible second trimester miscarriage. How Can I Prepare? Deciding to undergo prenatal genetic testing is a complex, personal decision. You may wish to consult with a genetic counselor to discuss the pros and cons of testing and how the test results may affect you and your family.Ask your health care provider to fully explain the benefits and risks of the procedure. Before having CVS, your health care provider will ask you to sign a consent form. You may be asked to drink fluids and refrain from urinating for a few hours before the test. A full bladder can help aid in the proper positioning of the uterus (fig. 2).  Figure 2 What Will Happen? There are two ways to perform CVS: through the cervix (transcervical CVS fig. 3) and through the abdomen (transabdominal CVS fig. 4). Transabdominal CVS appears to have a lower risk of miscarriage. If it’s not possible to reach the placenta through the abdomen, the health care provider may go through the cervix.
Women are often advised to rest for a few hours after CVS. Some women experience cramping or spotting (bleeding) for a day or two after the procedure. Results Test results are usually available in a few days to two weeks. More than 95% of women who undergo CVS will find out that their fetus does not have any detectable genetic abnormalities. CVS can accurately rule out or detect certain genetic abnormalities more than 99% of the time. Sometimes the results of the test are inconclusive. A woman with inconclusive CVS results may choose to have amniocentesis later in her pregnancy. Follow-up Your doctor may perform a follow-up ultrasound to make sure the fetus came through the procedure unharmed. What Are the Risks? Risks associated with CVS include miscarriage, birth defects, rupture of the amniotic sac, uterine infection, and vaginal bleeding. Frequently asked questions Q: Does CVS detect the same abnormalities that amniocentesis does? A: With the exception of neural tube defects such as spina bifida, CVS can rule out or detect the same genetic disorders as amniocentesis. Q: In what other ways does CVS differ from amniocentesis? A: CVS results are generally available from a few days to two weeks after the procedure, whereas amniocentesis results generally take two to four weeks. Q: If a birth defect is detected in my fetus, can it be treated? A: There are a few conditions that can be treated prenatally; however, the majority of congenital birth defects detected by CVS cannot be reversed. Future research may lead to additional treatments for specific congenital birth defects. Some couples choose to have an abortion if they learn their fetus has a severe abnormality. Review Date: January 16, 2007  A.D.A.M.'s health encyclopedia is accredited by URAC, also known as the American Accreditation Healthcare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial reviewers. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
|
||||
Existing Members
Featured Partner
|
Life Pilates Vancouver, pilates designed to build balance and efficient movement patterns. Just what a pregnant or post-partum body needs! Mention YourBabyYourWay.com to get 15% off a single lesson or $65 off a 10-lesson package. See all offers > |
FREE Resource Guide for |
Local Angle
|
 Encouragement + An Assist = Success Nine days past her due date, Sara Howe was awakened at 3:00AM when her water broke. Thrilled that the long wait was finally over, Sara and her husband David packed up and headed to PeaceHealth Southwest Medical Center. By 5:00AM they were comfortably settled into one of PeaceHealth Southwest’s Labor Delivery Recovery and Postpartum rooms, ready for action. But four hours later, Sara contractions had still not progressed so her midwife started her on Pitocin. Soon the contractions kicked in and Sara was well on her way. At around eight o’clock the next morning, it was time for Sara to start pushing. So she pushed. And she pushed, and she pushed, and she pushed. "The first few hours of pushing went by without me realizing the time," remarked Sara. "But around the fourth hour I started to wonder if I was still making progress. That is when the encouragement of my midwife, husband and the PeaceHealth Southwest nursing staff kept me going. It was like I had my own cheering section." Unfortunately, even with all the support and encouragement, Sara’s labor was not progressing because her baby’s head was tilted in the birth canal. Neither Sara or her midwife wanted her to have a Cesarean section after all that work, so her midwife suggested an assisted delivery. Read more > Share your story. Submit your story with a local angle, and you could receive a free gift if it is selected for publication. |
© 2012 PeaceHealth Southwest Medical Center | Vancouver, Washington | (360) 256-2000