title: Feasibility, accuracy and safety of chorionic villus sampling: a report of 10741 cases.
abstract: OBJECTIVE
  To evaluate the feasibility, accuracy and safety of chorionic villus sampling (CVS).
  
  
  METHODS
  Ten thousand seven hundred and forty one singleton pregnancies at risk of chromosome abnormalities (96.3%) and gene disorders (2.8%) were referred from 1990 to 1999 to the fetal medicine unit of a teaching hospital. CVS was performed transabdominally after 11 weeks, using a modified freehand ultrasonographically guided technique by 5 operators. Fetal karyotyping was obtained using a direct method before 1995 and was completed by cell culture after 1996. Failed results, feto-placental discrepancy and fetal loss were assessed.
  
  
  RESULTS
  Villi were sampled using extra-amniotic puncture (89.4%) and one sampling-device insertion (92.3%). The mean weight of the specimen was 15.2 +/- 6.0 mg. All attempts at sampling were successful, except eight (0.07%). The number of failed results following direct preparation, cell culture and both methods was 20 (0.19%), 23 (0.21%) and 2 (0.02%), respectively. Light maternal cell contamination occurred in less than 1% of the samplings after microscopic selection of the villi, and never interfered with the assessment of karyotyping. All 3 false-negative results (0.03%) were recorded after direct preparation and 2 were corrected by culture. The rate of chromosomal abnormalities confined to the placenta decreased from 1.08% before 1995 to 0.73% after 1996. True fetal mosaicisms were recorded in 7 cases (0.06%). The rate of fetal loss at <28 weeks was 1.64% in all pregnancies and 1.92% when CVS was performed before 13 weeks. Advanced maternal age was the single factor significantly associated with fetal loss.
  
  
  CONCLUSIONS
  CVS was feasible, accurate and safe in our institution, as a result of the increasing experience of the operators and the cytogeneticists.
authors.affiliation: Maternal and Fetal Medicine Unit, Pellegrin University Hospital, Bordeaux, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Brun
authors.forename: Raphaelle
authors.initials: R
authors.lastname: Mangione
authors.forename: Flore
authors.initials: F
authors.lastname: Gangbo
authors.forename: Frederic
authors.initials: F
authors.lastname: Guyon
authors.forename: Laurence
authors.initials: L
authors.lastname: Taine
authors.forename: Denis
authors.initials: D
authors.lastname: Roux
authors.forename: Brigitte
authors.initials: B
authors.lastname: Maugey-Laulom
authors.forename: Jacques
authors.initials: J
authors.lastname: Horovitz
authors.forename: Robert
authors.initials: R
authors.lastname: Saura
mesh_terms: D000328:Adult; D018929:Cell Culture Techniques; D015193:Chorionic Villi Sampling / Q000009:adverse effects / Q000379:methods*; D002869:Chromosome Aberrations / Q000145:classification*; D005240:Feasibility Studies; D005260:Female; D005313:Fetal Death / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D008423:Maternal Age; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D018566:Pregnancy, High-Risk; D015203:Reproducibility of Results; D012449:Safety