CVS vs amniocentesis

USE OF CVS AND AMNIOCENTESIS CVS utilizes either a catheter or needle to biopsy placental cells that are derived from the same fertilized egg as the fetus. During amniocentesis, a small sample of the fluid that surrounds the fetus is removed Amniocentesis or CVS is done when there is an increased risk that the baby may have genetic disorders or birth defects. It's often done if: You are 35 years of age or older by the time your baby is due. You have an increased risk of having a baby with a chromosome abnormality CVS results also come back quicker than amnio's. It may be difficult to find an experienced provider to do the test, though, because fewer doctors perform CVS than amnio. But, if you're at particular risk for neural tube defects, amnio is the clear choice — CVS won't detect these 1. The CVS is known as tests that gather fluids from the placental tissue that is called the chorionic villus while the amniocentesis is gathered from the amniotic sacs. 2. The amniocentesis is only conducted through the abdomen while the CVS can be done through both ways, through the cervix and the abdomen CVS is an alternative to amniocentesis. The advantage of CVS over amniocentesis is that a CVS test can be performed earlier, allowing more time for you to receive counseling and make decisions. Risk of miscarriage, although small, is higher with CVS than with amniocentesis and must be weighed against any benefits

Chorionic Villus Sampling and Amniocentesis

Amniocentesis is a prenatal diagnostic test that is usually performed between the 15th and 20th weeks of pregnancy. This procedure involves using an ultrasound to guide a thin, hollow needle through the abdomen of the mother and into the amniotic sac. The needle will then remove just enough amniotic fluid necessary to test for abnormalities Maybe: CVS and amniocentesis are tests that some patients will choose to have to help get a diagnosis. They allow testing of the baby's genes and help diagnosis genetic defects. These tests are not done routinely on everyone but rather on those who are at high risk for genetic diseases. Age > 35 or an abnormal blood test for Down syndrome would be examples of those who might consider this In CVS a small sample of the placenta (afterbirth) is taken for testing, whereas in amniocentesis a small amount of amniotic fluid - the water around your baby inside your uterus (womb) - is taken for testing. CVS is performed most commonly between 11 and 13 weeks. Amniocentesis is performed after 15 weeks. How accurate is CVS test

Therefore, the main difference between CVS and amniocentesis is the time during pregnancy in which it is performed. The advantage of CVS is receiving diagnostic information about fetal health earlier in pregnancy than with amniocentesis. In terms of accuracy, both tests are expected to provide accurate diagnostic answers I went with amnio, because I believe a CVS couldn't tell me the methylation (I can't remember exactly but there was something the later test could tell me that the CVS couldn't). Turns out I was having a girl, who had a full mutation and I decided to gamble (1/3 of the females have no symptoms, 1/3 have some learning disabilities and 1/3 are as. Amniocentesis is better than CVS for some women. You should have amniocentesis if you have had a baby with a neural tube defect, such as spina bifida, or if you or your partner has a neural tube.. The first amniocentesis can occur any time after the 15th week of pregnancy. CVS will most often be performed between the 10th and 12th weeks of pregnancy. The choice to test the baby for possible disorders or birth defects will inevitably be up to mom and dad

Prenatal Diagnosis: Amniocentesis and CVS - familydoctor

Chorionic villus sampling (CVS) and amniocentesis are tests performed in pregnancy to identify chromosomal abnormalities such as Down syndrome or genetic conditions such as cystic fibrosis. Prior to having a CVS or an amniocentesis it is important that you have a good understanding of the risks and limitations of each procedure Women who choose to have CVS or amniocentesis are often those at increased risk for genetic and chromosomal problems, in part because these tests are invasive and carry a small risk of miscarriage. The main advantage of CVS over amniocentesis is that you can have it done earlier — generally between 10 and 13 weeks of pregnancy Earlier alternatives are chorionic villus sampling (CVS) and early amniocentesis, which can be performed in the first trimester of pregnancy. Objectives: The objective of this review was to compare the safety and accuracy of all types of AC (i.e. early and late) and CVS (e.g. transabdominal, transcervical) for prenatal diagnosis

Q&A: CVS vs. amniocentesis? - TheBump.co

Objective: To estimate the procedure-related risk of miscarriage after amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis. Methods: A search of MEDLINE, EMBASE and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis 2in25months. Mar 4, 2021 at 9:50 AM. Like someone else mentioned, an amniocentesis will give you a yes or no, the NIPT will give you a likelihood. I would start with the NIPT and then do the amnio if they give you a high likelihood and you want to know definitively yes or no. I had an amnio with my first and it was all fine CVS vs. Amnio? I got a call from my provider yesterday that my NIPT (through Myriad) came back with a high risk for trisomy 18. I spent yesterday crying and researching because I really had no idea what this meant. The report was less than encouraging except for one part. My provider actually called me back a little bit later to point out this. Chorionic villus sampling (CVS) is a prenatal test in which a sample of chorionic villi is removed from the placenta for testing. The sample can be taken through the cervix (transcervical) or the abdominal wall (transabdominal). During pregnancy, the placenta provides oxygen and nutrients to the growing baby and removes waste products from the.

CVS actually has a slightly higher risk of miscarriage than amniocentesis. While amniocentesis is currently thought to have a miscarriage rate of around 0.5-1%, while CVS is thought to have a chance of between 1 and 2%. Whether you receive CVS or amniocentesis is dependent on when you are having a genetic test done MemphisMommy2012. Jul 4, 2012 at 9:17 AM. @bman2075, The M21 is extremely accurate (over 99%). The purpose of it is to give you the same results that you'd get from the amnio or CVS without the risks. There's no need to get the amnio if your already done the M21. Hopefully, your results will come in soon CVS and amniocentesis are diagnostic tests that can tell if a baby definitely has a serious condition by checking their chromosomes. This document is for pregnant women who are offered a CVS or..

The CVS procedure collects larger samples and provides faster results than amniocentesis. Results may be received between one to seven days. When is chorionic villus sampling (CVS) performed? CVS is usually performed between 10 and 13 weeks from your last menstrual period. CVS may be chosen over amniocentesis because it may be performed earlier. Chorionic Villus Sampling vs. Amniocentesis. Chorionic villus sampling and amniocentesis are both diagnostic prenatal tests. There are, however, a few main differences between the two. Chorionic villus sampling can be performed much earlier in a pregnancy, between 10 weeks pregnant and 13 weeks pregnant, whereas amniocentesis is generally. During amniocentesis, a small sample of the fluid that surrounds the fetus is removed. This fluid contains cells that are shed primarily from the fetal skin, bladder, gastrointestinal tract, and amnion. Typically, CVS is done at 10-12 weeks' gestation, and amniocentesis is done at 15-18 weeks' gestation CVS vs. Amniocentesis. GET ACCESS TO ALL PREMIUM CONTENT WITH NO ADS FOR $4.99/MONTH Watch Later . Comment. 4. Like. 4. Transcription: The main advantage of a CVS over an amniocentesis is when we can do it. A CVS is done between 10 1/2 weeks to 14 weeks; where an amnio you have to wait for 16 weeks in order to get the information. Depending on.

cfDNA vs Chorionic Villus Sampling (CVS)/Amniocentesis. There are several important differences between cfDNA screening and diagnostic testing, such as chorionic villus sampling (CVS) and amniocentesis. cfDNA is a screening test, which means that it cannot give a 'yes' or 'no' answer for whether a pregnancy has a chromosome condition. I think the amnio is better for a more comprehensive scan as it's later so can look for spina bifida at the same time. That being said, the CVS is substantially earlier and may make a potentially difficult decision easier to make. According to statistics, doing it in the 12th week is the safest for the fetus Prenatal Testing: Quad Screen vs. CVS vs. Amniocentesis. Posted on March 24, 2012 | 4 Comments. At some point during every older mother's pregnancy journey comes the dreaded Prenatal Testing. This is when all the statistics and risks we hear about genetic, chromosomal, neural tube, and other disorders come to a head to provide us a healthy.

In CVS, a sample of tissue is taken from the placenta. The main advantage of having CVS over amniocentesis is that CVS is performed earlier than amniocentesis, between 10 weeks and 13 weeks of pregnancy. The chance of miscarriage with CVS is slightly higher than the chance of miscarriage with amniocentesis What should you know about amniocentesis vs. CVS? Chorionic villus sampling (CVS) is a diagnostic test that evaluates cells from the placenta that contain the same genes as the fetus Most instances of mosaicism detected in CVS are not associated with a fetal abnormality and should be evaluated by further prenatal testing, i.e., amniocentesis or fetal blood sampling Amniocentesis vs. CVS Test. Amniocentesis and chorionic villus sampling (CVS) are both prenatal diagnostic tests, but there are a few major differences between the two. An amnio tests a small sample of amniotic fluid via a needle inserted into the abdomen. CVS, however, tests a small sample of tissue from the placenta and can be performed. CVS is usually done between the 10th and 12th weeks of pregnancy. Unlike amniocentesis (another type of prenatal test), CVS does not provide information on neural tube defects, such as spina bifida. For this reason, women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for neural tube defects

Fetal Testing: Amniocentesis and Chorionic Villus Sampling (CVS) November 10, 2020. October 3, 2020 by Biology Guidance. Genetic screening and genetic counselling provide information and options for prospective parents not even dreamed of 100 years ago. Newborn infants are routinely screened for several anatomical disorders (congenital hip. CVS and amniocentesis are two invasive techniques that can be utilized to rule out, definitively, Down Syndrome and other genetic diseases. Down Syndrome is an age-related that has a incidence of about 1/250 at age 35; and 1/100 in age 40 Chorionic Villus Sampling vs. Amniocentesis. CVS is used to get an early diagnosis of genetic and/or chromosomal abnormalities such as Down syndrome. It's offered when there's an increased risk of. Amniocentesis vs CVS ( Venn Diagram) Use Creately's easy online diagram editor to edit this diagram, collaborate with others and export results to multiple image formats. We were unable to load the diagram. You can edit this template on Creately's Visual Workspace to get started quickly. Adapt it to suit your needs by changing text and adding.

CVS or amniocentesis should be counseled about the benefits and risks of these procedures. The counselor should also discuss both the mother's and father's risk(s) for transmitting genetic abnormalities to the fetus. INTRODUCTION Chorionic villus sampling (CVS) and amniocentesis are prenatal diagnostic proce OBJECTIVE: To compare loss rates following amniocentesis and chorionic villus sampling (CVS) over time. METHODS: A retrospective cohort study of all amniocentesis and CVS procedures resulting in a normal karyotype from 1983-2003 at a single prenatal diagnostic referral center was conducted. Pregnancy loss rates for amniocentesis, CVS, and nonintervention groups (ie, those who had nuchal. Scope of NIPT vs CVS/amnio I am trying to determine if there is any advantage to the Panorama NIPT over amnio/cvs in Ontario - other than the fact that one is a non-invasive screening test, and the others are invasive and diagnostic Chorionic villus sampling or CVS is a prenatal test, one done during pregnancy, to diagnose any type of chromosomal abnormality in a fetus or an unborn baby. Genetic disorders and conditions like Down syndrome can be detected with the help of this test. There is another test, which is usually considered a substitute, called amniocentesis test When it comes to prenatal genetic testing, chorionic villus sampling (CVS) and amniocentesis (amnio) are rarely the first types of tests discussed.Most doctors tend to recommend prenatal screenings for women under 35.. But screenings have their shortcoming— they miss at least half of certain types of genetic problems and only provide a likelihood of your baby having a particular genetic.

cell-free DNA (cfDNA) vs Amniocentesis & Chorionic Villus Sampling (CVS) To the Point - cfDNA is a screening test, whereas amniocentesis and CVS are considered diagnostic tests. Although sensitivity and specificity are quite high for certain conditions, cfDNA CANNOT be substituted for diagnostic testing such as amniocentesis in terms of the. Free-Cell DNA vs CVS and AMNIO... I'm surprised no one here has heard of Free-Cell DNA testing All I've read is that this test for Downs Syndrome and possible other genetic birth defects, but nothing HD specific. It's claiming to be less invasive than cvs and amnio.. FISH, or fluorescence in situ hybridization, is a test that can be done on the cells from a chorionic villus sampling (CVS) or amniocentesis procedure. FISH can provide rapid results (usually within 48 to 72 hours) for limited chromosome conditions. Most labs offer FISH testing on CVS or amniocentesis cells for chromosomes 21, 18, 13, and the. Simulator for Amniocentesis, CVS and Intrafetal procedure

Difference Between Amniocentesis and CV

  1. Chorionic villus sampling (CVS) and amniocentesis are diagnostic tests.Diagnostic tests can tell if your baby definitely has a serious condition by checking their chromosomes for genetic information
  2. al or a transcervical approach
  3. Occasionally the CVS is unable to be performed because of the placental position which will be discussed with you at the time of the scan. In these circumstances you are offered an amniocentesis at 15-16 weeks. After the VS There may be some discomfort due to bruising and some cramps may be experienced. 2 Paracetamol tablets can be taken to eas
  4. CVS is done between 10-12 weeks of pregnancy while amniocentesis is done between 15-20 weeks. For many women, the thought of knowing earlier if there is a problem makes CVS more attractive. I considered CVS and amniocentesis when I was pregnant because I was over 35
Prenatal diagnosis

Introduction. The risks of pregnancy loss after chorionic villus sampling (CVS) and amniocentesis in singleton pregnancies are well described 1, 2, but there is a real paucity of data regarding the safety of prenatal diagnostic techniques in twin pregnancies.Most of the currently published guidelines on prenatal diagnostic techniques do not address this issue 3-6 During the procedure, ultrasound guidance is used so that the doctor can see the placenta's position. CVS can also be done in a multiple pregnancy; in this case both the transabdominal and transcervical methods of collection may be used. Amniocentesis. During amniocentesis, the doctor uses ultrasound to locate an open pocket of amniotic fluid To assess the safety and diagnostic accuracy of chorionic villus sampling (CVS), Canadian investigators compared CVS with amniocentesis in a multicenter randomized trial of 2787 mothers older than 35 years. About half the women underwent CVS at nine to 12 weeks gestation, and the remainder underwent amniocentesis at 15 to 17 weeks. Overall.

Amniocentesis. Amniocentesis is a prenatal test. During amniocentesis, an ultrasound transducer is used to show a baby's position in the uterus on a monitor. A sample of amniotic fluid, which contains fetal cells and chemicals produced by the baby, is then withdrawn for testing. Amniocentesis is a procedure in which amniotic fluid is removed. The electronic search yielded 2943 potential citations, from which 12 controlled studies for amniocentesis and seven for CVS were selected for inclusion in the systematic review. A total of 580 miscarriages occurred following 63 723 amniocentesis procedures, resulting in a weighted risk of pregnancy loss of 0.91% (95% CI, 0.73-1.09%) Learn more about the benefits of diagnostic genetic tests in the second post in this series on amnio and CVS. Or check out our Complete Guide to Prenatal Testing ebook. Share the article. About Amy. Amy Kiefer is a researcher by training, and earned her Ph.D. from the University of Michigan. She currently lives in the Bay Area with her husband.

What's the difference between CVS and amniocentesis

  1. An alternative to CVS is a test called amniocentesis. This is where a small sample of amniotic fluid, the fluid that surrounds the baby in the womb, is removed for testing. It's usually carried out between the 15th and 18th week of pregnancy, although it can be performed later than this if necessary
  2. CVS vs Amnio CVS may be preferred by parents who desire a possible diagnosis of a genetic or chromosomal disorder before 14 weeks of pregnancy. This is because the test can be done earlier (10 weeks) and also because the cells obtained through CVS are live and fresh (unlike cells obtained from amniotic fluid), making the test results available.
  3. FINDINGS: The actual risk of miscarriage following amniocentesis or chorionic villus sampling (CVS) has been controversial. ACOG provides an estimated overall risk of fetal loss due to invasive testing of 0.1% - 0.3% above the background miscarriage rate. Previous papers that showed an increased rate of miscarriage included fetuses that may have been compromised or [
  4. CVS vs. Amniocentesis New parents considering prenatal testing often make a choice between CVS and amniocentesis (often referred to as amnio). Both tests involve removing tissue from inside the womb (in the case of amniocentesis, amniotic fluid that contains fetal cells) and are considered equally safe

Chorionic villus sampling was formally introduced in the 1980s and has become established as the prenatal diagnostic procedure in the first trimester after an early feasibility report in 1968 by Mohr. 16b The indications for CVS are similar to those discussed for amniocentesis. CVS also offers the advantage of early and rapid diagnosis for. Pre-implantation genetic diagnosis PGT-M (PGD) allows genetic analysis of an early embryo, before it is transferred into the uterus. PGT-M (PGD) is similar to other invasive prenatal screening tests, such as amniocentesis and chorionic vilus sampling (CVS), except it is done prior to implantation

Amniocentesis vs CVS . I verden av omfattende nyskapende testing, er prenataleksamen for å bestemme utviklingen av fosteret ganske rikelig. To av de vanligste metodene for å kontrollere utviklingen er amniocentese og CVS eller formelt kalt som kororisk villusprøve CVS can be done early in pregnancy (earlier than amniocentesis), and results are usually obtained within 10 days. Getting this kind of information early allows a woman to make choices in the.

Amniocentesis and non-invasive prenatal testing (NIPT) are two very different techniques that are used to check for the same thing. Both tests are usually only carried out if your medical history or the Nuchal Translucency scan suggest that there is a high probability of a chromosomal abnormality. Amniocentesis and CVS Amniocentesis (also referred to as an amniotic fluid test or, informally, an amnio) is a medical procedure used primarily in prenatal diagnosis of chromosomal abnormalities and fetal infections as well as for sex determination.In this procedure, a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus Information for you This leaflet has been updated Up-to-date information is available on the RCOG website: https://www.rcog.org.uk/en/patients/patient-leaflet The main advantage of this test is that it's quick. Your doctor may recommend it over amnio or CVS if she wants to check your baby for a chromosomal defect or blood disorder and needs to know the results fast. It may take a few weeks to get the results of amniocentesis, whereas PUBS can provide an answer in a few days

Amniocentesis and CVS - What's the Difference? - 3 Kids and U

Chorionic villus sampling (CVS) is a procedure that may be performed during pregnancy to diagnose certain genetic or chromosomal disorders. CVS involves having a biopsy of the developing placenta. The chorionic villi are the tiny units that make up the placenta and have the same genetic make-up as the fetus. More detailed information about CVS. Chorionic villus sampling, more commonly called CVS, is a prenatal test used to identify birth defects and disorders. CVS is usually performed 10 to 12 weeks after your last menstrual period. Chorionic villi are microscopic, finger-like wisps of placental tissue formed from your fertilized egg. Because villi cells normally have the same genetic. Amniocentesis is generally performed at 105 to 125 days post last menstrual period (LMP) and TA CVS at 63 to 76 days post LMP. This study will compare the safety and accuracy of transabdominal amniocentesis and TA CVS, each performed during the same modified gestational age window of 77 to 104 days post LMP Procedure related risk of CVS vs. amniocentesis . Dear Colleague, Since the introduction into clinical practice of midtrimester amniocentesis and first trimester chorionic villus sampling, the obstetrical risks associated with invasive testing have been the subject of multiple studies at the international level. Efficacy of the procedures. CVS and Amniocentesis; When: 9-10 weeks and over: 11-14 weeks: 15-22 weeks: CVS: 10-13 weeks Amniocentesis: 15-16 weeks and over: How performed: Maternal blood: Maternal blood + ultrasound: Maternal blood: Invasive procedure: Risks: None: None: None: Risks of miscarriage CVS 1/455 Amniocentesis 1/900: T21 detection rate >99%: 85%: 81% >99

should i have cvs or amniocentesis? Answers from Doctors

Subject: Re:Amnio vs. CVS Anonymous CVs here with Dr stern too- he was top notch but a dorky bedside manner- no way rude or intimidating- but he's got his own style- he's just fine overall since he's done cvs so many times- and you do feel confident in him. Amniocentesis vs CVS. Both Amniocentesis and Chorionic villus sampling are prenatal tests used to detect problems related to the foetus and other chromosomal disorders. 1. Amniocentesis is done around \(16\) to \(20\) weeks of pregnancy, and CVS is conducted around \(9\) to \(12\) weeks of pregnancy. 2 Amniocentesis. Indications for Amnio. Maternal age >35 y/o (accounts for majority) Hi or Low MSAFT results (10-20%) Previous chromosomal abnormalities (similar to CVS) Maternal anxiety. Choroid plexus cyst >10mm, bilateral) Lung maturity mecithin sphingomyelin ratio (L/S ratio) means lungs are mature. Diagnose fetal trauterine infection

Video: Is CVS or amniocentesis more accurate

Prenatal Genetic Testing Options, Explained: CVS and Amnio

Amniocentesis vs CVS | Editable Venn Diagram Template on

Fragile X - CVS or Amniocentesis? — The Bum

Prenatal Diagnosis: Amniocentesis and CVS - American

Amniocentesis is a little trickier with twins than it is with single babies. Make sure your doctor or technician has experience doing amniocentesis with multiples CVS/Amnio vs harmony. Sarah_1200. Posted 10/13/14. Apologies if this turns in to a ramble but that pretty much reflects my state of mind! On Friday we were told our baby has a cystic hygroma. I've had bloods for infection and have a scan in 3 weeks to look at the heart but am struggling with the karyotyping issue FISH, or Fluorescence In Situ Hybridization, is a diagnostic prenatal test which looks for a few common chromosomal abnormalities. A fluorescent dye is used to visualize and map genetic material in cells. FISH is usually performed with the same genetic material gathered for testing during CVS or amniocentesis. The advantage of FISH testing is that results are often available in as little as 24.

Amniocentesis and CVS babyMed

Chorionic villus sampling (CVS) may be safer than early amniocentesis for early prenatal diagnosis of cytogenetic abnormalities. The risk of miscarriage with CVS is 1% to 1.5% but the risk of maternal infection appears to be higher with CVS than with amniocentesis. Cytogenetic analyses using such samples allow for an early gestational testing. Anxiety and depression scores in CVS and amniocentesis The alternative method - amniocentesis (AC) - is usually performed after 15 weeks. The advantage of differences between CVS vs. first trimester controls, AC vs. second trimester controls, and CVS vs. AC with respect to maternal age, partner's age,.

Procedure-related risk of miscarriage after CVS or

amniocentesis vs cvs Answers from Doctors HealthTa

Chorionic villus sampling (CVS) This is a 'diagnostic test' and one advantage of the CVS test over amniocentesis is that it can be carried out early in pregnancy, at about 11-13 weeks. At present this test isn't available everywhere, but can show up a number of disorders in your developing baby, including Down syndrome, though not spina bifida Chorionic Villi Sampling (CVS) An early diagnosis (between 10-12 weeks of gestation) is possible using chorionic villi sampling (CVS). This is done under ultrasound control, transabdominal or. The NHS Fetal Anomaly Screening Programme (FASP) is pleased to launch a new counselling resource leaflet: ' Chorionic villus sampling (CVS) and amniocentesis: information for parents '. The new leaflet includes new illustrations showing what amniocentesis and CVS tests involve. Most pregnancies progress with no problems but some women and.

Difference Between Amniocentesis and Chorionic VillusAmniocentesis & CVSFetal Testing: Amniocentesis and Chorionic Villus SamplingChorionic villus sampling – DR

Difference Between Amniocentesis and Chronic Villus Sampling Amniocentesis vs Chronic Villus Sampling Pregnancy is a worrying time for expectant mothers. In today's medically enhanced world, various tests are available to detect any problems with the growing foetus. During pregnancy, the expectant mother will undergo several sets of blood tests Summary - Amniocentesis vs Cordocentesis. Amniocentesis and cordocentesis are two prenatal tests which are invasive procedures. Both tests use a very thin needle to extract the sample. Amniocentesis test is done on a small sample of amniotic fluid while cordocentesis test is done on a blood sample of the umbilical cord. Thus, this is the key. Dr. Joseph Woo. Amniocentesis. Tapping of amniotic fluid had been practised for over a 100 years although many cases had not been recorded. In the literature, transabdominal amniocentesis in the third trimester has been reported by Prochownick, Von Schatz and Lambl in 1877 and Schatz in the 1890s.In 1919 there was a report from Hinkel describing release of amniotic fluid from a patient with. Chorionic villus sampling (CVS)* Amniocentesis* The sample collected during invasive testing (CVS or amniocentesis) can be tested several different ways: Chromosomal study (karyotype)* Chromosomal microarray (aCGH)* Single gene test or panel of genes* *See glossary for descriptions of each test and discussions of the benefits and limitations of. Amniocentesis You might be offered amniocentesis as an alternative to CVS after 15 weeks of pregnancy. Sometimes, you might be offered amniocentesis if you've had CVS, but the CVS results aren't clear. Amniocentesis is used to take a sample of the fluid that surrounds your baby in the uterus