Chorionic villus sampling

Genetic MedicineChorionic villus sampling has gained importance as a tool for early cytogenetic diagnosis with a shift toward first trimester screening.First trimester screening using nuchal translucency and biomarkers is effective for screening.Chorionic villus sampling generally is performed at 10-12 weeks by either the transcervical or transabdominal approach.There are two methods of analysis; the direct method and the culture method.While the direct method may prevent maternal cell contamination, the culture method may be more representative of the true fetal karyotype.There is a concern for mosaicism which occurs in approximately 1% of cases, and mosaic results require genetic counseling and follow-up amniocentesis or fetal blood sampling.In terms of complications, procedure-related pregnancy loss rates may be the same as those for amniocentesis when undertaken in experienced centers.When the procedure is performed after 9 weeks gestation, the risk of limb reduction is not greater than the risk in the general population.At present, chorionic villus sampling is the gold standard method for early fetal karyotyping; however, we anticipate that improvements in noninvasive prenatal testing methods, such as cell free fetal DNA testing, will reduce the need for invasive procedures in the near future. Key words: Chorionic villus sampling (CVS).in cases with mosaicism.Currently, noninvasive prenatal testing (NIPT) is emerging as an effective method of screening for aneuploidy.This review briefly summarizes contemporary issues relating to the use of CVS. Counseling for Aneuploidy Screening or Invasive Diagnostic TestingThe American College of Obstetricians and Gynecologists (ACOG) has recommended that screening and invasive diagnostic testing for aneuploidy should be available to all women, regardless of maternal age [1,2].Every women should be counseled nondirectively on each screening and diagnostic Chorionic villus sampling