Chorionic villus sampling (CVS) is a prenatal diagnostic procedure introduced in 1968, involving the removal of chorionic villi from the placenta for genetic testing, typically performed between 10 and 12 weeks of gestation. The procedure carries risks such as miscarriage and infection, but is considered reliable, with a success rate that has improved over the years. Indications for CVS include abnormal ultrasound findings, family history of genetic disorders, and advanced maternal age.

2. HAFIZ M WASEEM UNIVERSITY OF
EDUCATION LAHORE

3. CHORIONIC VILLUS
SAMPLING:

4. CONTENT:
 HISTORY
 STATEMENT
 PROCEDURE
 RISK
 RELIABILITY
 POSSIBLE REASON FOR CVS
 LIMITATIONS
 REFRENCES

5. HISTORY:
 In 1968 Mohr in Scandinavia introduced the idea of antenatal genetic diagnosis using sample
from chorionic villi. He performed transcervical biopsy of the chorionic villi, under direct
endoscopic vision, with the help of endoscope. He reported a 96% success rate in obtaining
chorionic material but with a high incidence of bleeding, infection and failed culture.
 The first successful prenatal diagnostic use of chorionic villi biopsy was apparently reported
in 1975 from the Department of Obstetrics and Gynaecology at the Tietung Hospital in
Anshan, China, where fetal sex was diagnosed for the purpose of sex pre-selection. They
performed test on 100 patients and placental material was obtained with the help of syringe
suction. They claimed to have 6 wrong diagnosis out of 99 successful diagnosis and only 4 prenatal
losses. Investigators in the United States were, however unable to duplicate the results
 In 1983, Ward in London performed transcervical chorionic sampling under ultrasonic guidance .
His group reported 67% sampling success rate, including 7 patients for the diagnosis of
haemoglobinopathies.
 The Brambati group in Milan demonstrated in 1983 that with ultrasonic guidance, success rate of
obtaining chorionic material rose from 75% to 96%.

6. EXPLANATION:
 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:
a. the cervix (transcervical)
b. the abdominal wall (transabdominal).
 During this test,small portion from placenta called chorionic villi is taken .Chorionic villi are
tiny parts of placenta ,that are formed from fertilized egg so,they have the same genes as the
fetus.

7. Placenta:
That’s how its look…….

8. Placenta:
Little detail……..

9. Both in ultrasound guidance:

10. Risk:
 the possibility of miscarriage….1/100
 an amniotic fluid leak may develope
 Infection
 Vaginal bleeding
 Cramping
 Pain in inserted site

11. Possible reason for having cvs:
 Abnormal first trimester screen results
 Increased abnormal ultrasound findings
 Family history of a chromosomal abnormalities or other genetic disorder.
 Parents are known carriers for a 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.
 Couples who already have had a child with a birth defect or have a family history of certain birth defects.
 Couples with a parent known to carry a chromosomal abnormality or genetic disease
 Pregnant women with other abnormal genetic results.

12. Time of gestation should be:
 Chorionic Villus Sampling (CVS) is usually performed between 10 and 12 weeks after
your last menstrual period.

13. Reliability:
 Chorionic villus sampling is considered to be a very reliable test, but there is
approximately a 1% chance of false positive results. One reason is that certain genetic
conditions may exist in the placenta but not in the fetus itself, such as mosaicism of the DNA.
This might require an amniocentesis at week 16–17 for confirmation.

14. Refrences:
 Alter, B.P., Modell, C.B., Fairweather, D., Hobbins, J.C., Mahoney, M.J., Frigoletto, F.D.,
Sherman, A.S. & Nathan, D.G. (1976) Prenatal diagnosis of hemoglobinopathies: a review
of 15 cases. New England Journal of Medicine, 295,1437
 Niazi, M., Coleman, D.V. and Loeffler, F.E. (1981). Trophoblast sampling in early
pregnancy. Culture of rapidly dividing cells from immature placental villi. Br. J. Obstet.
Gynaecol., 88,1081-5
 Westin, B. (1954). Hysteroscopy in early pregnancy. Lancet, 11,872

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