Editing Chorionic villus sampling

{{Short description|Type of prenatal diagnosis done to determine chromosomal or genetic disorders in the fetus}}
{{Infobox medical intervention
| Name        = Chorionic villus sampling 
| Image       = Chorionic villi - high mag.jpg
| Caption     = [[Micrograph]] showing chorionic villi—the tissue that is collected in CVS. [[H&E stain]].
| ICD10       = 16603-00 
| ICD9        = 75.33 
| MedlinePlus = 003406
| MeshID      = D015193 
| Synonyms  = CVS
}}

'''Chorionic villus sampling''' ('''CVS'''), sometimes called "chorionic ''villous'' sampling" (as "villous" is the adjectival form of the word "villus"),<ref>A [[PubMed]] search yields 168 papers using ''chorionic villous'' as of June 15, 2011.</ref> is a form of [[prenatal diagnosis]] done to determine [[chromosomal abnormalities|chromosomal]] or [[genetic disorders]] in the [[fetus]]. It entails [[sampling (medicine)|sampling]] of the [[chorionic villus]]                              ([[placenta]]l tissue) and testing it for chromosomal abnormalities, usually with [[Fluorescence in situ hybridization|FISH]] or [[Polymerase chain reaction|PCR]]. CVS usually takes place at 10–12 weeks' gestation, earlier than [[amniocentesis]] or [[percutaneous umbilical cord blood sampling]]. It is the preferred technique before 15 weeks.<ref name=":0">{{Cite journal |last=Alfirevic |first=Z. |last2=Sundberg |first2=K. |last3=Brigham |first3=S. |date=2003 |editor-last=Alfirevic |editor-first=Zarko |title=Amniocentesis and chorionic villus sampling for prenatal diagnosis |journal=The Cochrane Database of Systematic Reviews |issue=3 |pages=CD003252 |doi=10.1002/14651858.CD003252 |issn=1469-493X |pmc=4171981 |pmid=12917956}}</ref>

CVS was performed for the first time in [[Milan]] by Italian biologist [[Giuseppe Simoni]], scientific director of [[Biocell Center]], in 1983.<ref name="Lancet">{{Cite journal |last=Brambati |first=B. |last2=Simoni |first2=G. |year=1983 |title=Diagnosis of fetal trisomy 21 in first trimester |journal=The Lancet |volume=1 |issue=8324 |pages=586 |doi=10.1016/S0140-6736(83)92831-3 |pmid=6131275 |s2cid=42553451}}</ref>
Use as early as eight weeks in special circumstances has been described.<ref name="pmid12066086">{{Cite journal |last=Wapner |first=Ronald J. |last2=Evans |first2=Mark I. |last3=Davis |first3=George |last4=Weinblatt |first4=Vivian |last5=Moyer |first5=Sue |last6=Krivchenia |first6=Eric L. |last7=Jackson |first7=Laird G. |year=2002 |title=Procedural risks versus theology: Chorionic villus sampling for Orthodox Jews at less than 8 weeks' gestation |journal=American Journal of Obstetrics and Gynecology |volume=186 |issue=6 |pages=1133–6 |doi=10.1067/mob.2002.122983 |pmid=12066086}}</ref> It can be performed in a transcervical or transabdominal manner.<ref name=":0" /> Although this procedure is mostly associated with testing for [[Down syndrome]], overall, CVS can detect more than 200 disorders.<ref>{{MedlinePlusEncyclopedia|003406|Chorionic villus sampling}}</ref>

==Indications==
Possible reasons for having a CVS can include:{{cn|date=February 2025}}
*Abnormal first trimester screen results
*Increased [[nuchal translucency]] or other abnormal [[obstetric ultrasonography|ultrasound]] findings
*Family history of a [[chromosomal abnormality]] or other [[genetic disorder]]
*Parents are known carriers for a [[genetic disorders|genetic disorder]]
* Advanced maternal age (maternal age above 35). AMA is associated with increase risk of [[Down's syndrome]] and at age 35, risk is 1:400.{{citation needed|date=February 2020}} Screening tests are usually carried out first before deciding if CVS should be done.

==Risks==
The risk of miscarriage in CVS is estimated to be potentially as high as 1–2%. However some recent research has suggested that only a very small number of miscarriages that occur after CVS are a direct result of the procedure.<ref>{{Cite web |title=Chorionic villus sampling - Risks |url=http://www.nhs.uk/conditions/chorionic-villus-sampling/Pages/Risks.aspx |access-date=2016-05-24 |website=[[NHS Choices]]}} Page last reviewed: 06/08/2015</ref> Apart from a risk of miscarriage, there is a risk of infection and [[amniotic fluid]] leakage. The resulting amniotic fluid leak can develop into a condition known as [[oligohydramnios]], which is low amniotic fluid level. If the resulting oligohydramnios is not treated and the amniotic fluid continues to leak it can result in the baby developing hypoplastic lungs (underdeveloped lungs).<ref>{{Cite journal |last=Wu |first=Chun-Shan |last2=Chen |first2=Chung-Ming |last3=Chou |first3=Hsiu-Chu |date=February 2017 |title=Pulmonary Hypoplasia Induced by Oligohydramnios: Findings from Animal Models and a Population-Based Study |journal=Pediatrics and Neonatology |volume=58 |issue=1 |pages=3–7 |doi=10.1016/j.pedneo.2016.04.001 |issn=2212-1692 |pmid=27324123 |doi-access=free}}</ref><ref>{{Cite journal |last=Spong |first=C. Y. |date=December 2001 |title=Preterm premature rupture of the fetal membranes complicated by oligohydramnios |journal=Clinics in Perinatology |volume=28 |issue=4 |pages=753–759, vi |doi=10.1016/s0095-5108(03)00075-7 |issn=0095-5108 |pmid=11817187}}</ref>

Additionally, there is also mild risk of limb reduction defects associated with CVS, with the risk being higher the earlier the procedure is carried.<ref>{{Cite journal |year=1995 |title=Chorionic villus sampling and amniocentesis: recommendations for prenatal counseling. Centers for Disease Control and Prevention |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/00038393.htm |journal=MMWR |volume=44 |issue=RR-9 |pages=1–12 |pmid=7565548}}</ref>

It is important after having CVS that the [[obstetrician]] follows the patient closely to ensure the patient does not develop infection.{{cn|date=February 2025}}

==Chorionic villi and stem cells==
Recent studies have discovered that chorionic villi can be a rich source of fetal stem cells, multipotent [[mesenchymal stem cells]].<ref name="wash_post">{{Cite news |last=Weiss |first=Rick |date=2007-01-08 |title=Scientists See Potential In Amniotic Stem Cells |url=https://www.washingtonpost.com/wp-dyn/content/article/2007/01/07/AR2007010700674.html |access-date=2010-04-23 |work=The Washington Post}}</ref><ref name="nature">{{Cite journal |last=De Coppi |first=Paolo |last2=Bartsch |first2=Georg |last3=Siddiqui |first3=M Minhaj |last4=Xu |first4=Tao |last5=Santos |first5=Cesar C |last6=Perin |first6=Laura |last7=Mostoslavsky |first7=Gustavo |last8=Serre |first8=Angéline C |last9=Snyder |first9=Evan Y |last10=Yoo |first10=James J |last11=Furth |first11=Mark E |last12=Soker |first12=Shay |last13=Atala |first13=Anthony |year=2007 |title=Isolation of amniotic stem cell lines with potential for therapy |journal=Nature Biotechnology |volume=25 |issue=1 |pages=100–6 |doi=10.1038/nbt1274 |pmid=17206138 |s2cid=6676167}}</ref><ref name="urlStem Cells - BiocellCenter">{{Cite web |title=Stem Cells – BiocellCenter |url=http://www.biocellcenter.com/en/services_research/stem_cells/ |url-status=dead |archive-url=https://web.archive.org/web/20100111035407/http://www.biocellcenter.com/en/services_research/stem_cells/ |archive-date=11 January 2010 |access-date=2010-01-11}}</ref>

A potential benefit of using fetal stem cells over those obtained from embryos is that they side-step [[stem cell controversy|ethical concerns]] among anti-abortion activists by obtaining pluripotent lines of undifferentiated cells without harm to a fetus or destruction of an embryo. These stem cells would also, if used to treat the same individual they came from, sidestep the donor/recipient issue which has so far stymied all attempts to use donor-derived stem cells in therapies.{{citation needed|date=August 2015}}

Artificial heart valves, working tracheas, as well as muscle, fat, bone, heart, neural and liver cells have all been engineered through use of fetal stem cells.<ref name="urlStem cells scientific updates - BiocellCenter">{{Cite web |title=Stem cells scientific updates – BiocellCenter |url=http://www.biocellcenter.com/en/services_research/scientific_updates/ |url-status=dead |archive-url=https://web.archive.org/web/20100111035235/http://www.biocellcenter.com/en/services_research/scientific_updates/ |archive-date=11 January 2010 |access-date=2010-01-11}}</ref>

The first fetal stem cells bank in US is active in Boston, Massachusetts.<ref name="European Biotech Company Biocell Center Opens First U.S. Facility for Preservation of Amniotic Stem Cells in Medford, Massachusetts">{{Cite news |date=2009-10-22 |title=European Biotech Company Biocell Center Opens First U.S. Facility for Preservation of Amniotic Stem Cells in Medford, Massachusetts |url=https://www.reuters.com/article/pressRelease/idUS166682+22-Oct-2009+PRN20091022 |url-status=dead |archive-url=https://web.archive.org/web/20091030150358/https://www.reuters.com/article/pressRelease/idUS166682%2B22-Oct-2009%2BPRN20091022 |archive-date=October 30, 2009 |access-date=2010-01-11 |work=Reuters}}</ref><ref name="urlEuropes Biocell Center opens Medford office - Daily Business Update - The Boston Globe">{{Cite news |date=2009-10-22 |title=Europe's Biocell Center opens Medford office – Daily Business Update – The Boston Globe |url=http://www.boston.com/business/ticker/2009/10/europes_biocell.html |url-status=live |archive-url=https://web.archive.org/web/20100112204948/http://www.boston.com/business/ticker/2009/10/europes_biocell.html |archive-date=12 January 2010 |access-date=2010-01-11}}</ref><ref name="urlThe Ticker - BostonHerald.com">{{Cite web |title=The Ticker - BostonHerald.com |url=http://www.bostonherald.com/business/general/view/20091022the_ticker |url-status=dead |archive-url=https://web.archive.org/web/20120921064743/http://www.bostonherald.com/business/general/view/20091022the_ticker |archive-date=2012-09-21 |access-date=2010-01-11}}</ref><ref name="urlBiocell partner with largest New England's hospital group to preserve amniotic stem cell | PRNews">{{Cite press release |title=Biocell partner with largest New England's hospital group to preserve amniotic stem cell |url=http://www.prnewswire.com/news-releases/biocell-center-corporation-partners-with-new-englands-largest-community-based-hospital-network-to-offer-a-unique-service-in-amniotic-fluid-stem-cell-preservation-86848157.html |access-date=2010-03-10 |url-status=live |archive-url=https://web.archive.org/web/20100314110723/http://www.prnewswire.com/news-releases/biocell-center-corporation-partners-with-new-englands-largest-community-based-hospital-network-to-offer-a-unique-service-in-amniotic-fluid-stem-cell-preservation-86848157.html |archive-date=14 March 2010}}</ref>

==Limitations==
A small percentage (1-2%) of pregnancies have [[confined placental mosaicism]], where some but not all of the [[placenta]]l cells tested in the CVS are abnormal, even though the pregnancy is unaffected.<ref name="Wapner">{{Cite journal |last=Wapner |first=Ronald J. |year=2005 |title=Invasive Prenatal Diagnostic Techniques |journal=Seminars in Perinatology |volume=29 |issue=6 |pages=401–4 |doi=10.1053/j.semperi.2006.01.003 |pmid=16533654}}</ref> Cells from the mother can be mixed with the [[placenta]]l cells obtained from the CVS procedure. Occasionally if these maternal cells are not completely separated from the [[placenta]]l sample, this can lead to discrepancies with the results.  This phenomenon is called Maternal Cell Contamination (MCC).<ref name=Wapner/>  CVS cannot detect all birth defects.  It is used for testing [[chromosomal abnormalities]] or other specific [[genetic disorders]] only if there is family history or other reason to test.{{citation needed|date=August 2015}}

==See also==
* [[Amniocentesis]]
* [[Cell-free fetal DNA]]
* [[Elective genetic and genomic testing]]
* [[Percutaneous umbilical cord blood sampling]]
* [[Prenatal testing]]

==References==
{{Reflist|30em}}

== External links ==
* [http://www.marchofdimes.org/pregnancy/chorionic-villus-sampling.aspx Chorionic Villus Sampling - March of Dimes]
* {{MedlinePlusEncyclopedia|003406}}
* [https://web.archive.org/web/20060427090241/http://www.clevelandclinic.org/health/health-info/docs/0400/0417.asp?index=4028&src=news Cleveland Clinic]
* [https://web.archive.org/web/20090525022510/http://teresastrasser.com/blog/2009/04/cvs-order-now-and-get-six-months-of-worry-free-pregnancy/ CVS Test: Six Months of Worry Free Pregnancy]
* [https://www.nytimes.com/slideshow/2007/08/01/health/100194Chorionicvillussamplingseries_index.html Chorionic Villus Sampling] - slideshow by ''[[The New York Times]]''

{{Obstetrical procedures}}
{{Pregnancy}}
{{Authority control}}

{{DEFAULTSORT:Chorionic Villus Sampling}}
[[Category:Tests during pregnancy]]
[[Category:Prenatal sex discernment]]