title: Chorionic villus sampling before multifetal pregnancy reduction.
abstract: OBJECTIVE
  This study was undertaken to determine the technical feasibility and accuracy of chorionic villus sampling before multifetal pregnancy reduction and to determine whether sampling increases the pregnancy loss rate after the reduction procedure.
  
  
  METHODS
  Between January 22, 1986, and January 20, 2000, a total of 1183 patients underwent first-trimester multifetal pregnancy reduction at Mount Sinai Medical Center. Chorionic villus sampling was attempted in 86 patients before the reduction procedure. Information on the technical success and accuracy of chorionic villus sampling, as well as pregnancy outcome, was collected on all patients. Pregnancy loss rates before 24 weeks' gestation in patients undergoing chorionic villus sampling before multifetal pregnancy reduction were compared with rates in patients not undergoing sampling.
  
  
  RESULTS
  Chorionic villus sampling was successfully completed in 85 (98.8%) of 86 patients in whom sampling was attempted. Of 166 fetuses, 165 (99.4%) were successfully sampled. Of 165 fetuses, 3 (1.8%) had karyotypic abnormalities. Sampling errors were probably made in 2 (1.2%) of 165 fetuses. Of the 73 patients who have been delivered or are beyond 24 weeks' gestation, only 1 patient (1.4%) had a pregnancy loss after the multifetal pregnancy reduction.
  
  
  CONCLUSIONS
  Chorionic villus sampling before multifetal pregnancy reduction is technically feasible and accurate, with an acceptably low sampling error rate. Chorionic villus sampling before multifetal pregnancy reduction appears to be safe and does not increase the risk of loss after the reduction procedure.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Science, Mount Sinai Medical Center, New York, New York, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Eddleman
authors.forename: J L
authors.initials: JL
authors.lastname: Stone
authors.forename: L
authors.initials: L
authors.lastname: Lynch
authors.forename: R L
authors.initials: RL
authors.lastname: Berkowitz
mesh_terms: D000328:Adult; D015193:Chorionic Villi Sampling; D000013:Congenital Abnormalities / Q000196:embryology / Q000235:genetics; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007621:Karyotyping; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal; D011261:Pregnancy Trimester, First; D012449:Safety