title: Transcervical chorionic villus sampling in multiple pregnancies using a biopsy forceps.
abstract: OBJECTIVE
  The aim of this study was to assess the effectiveness and safety of chorionic villus sampling (CVS) performed in multiple pregnancies by means of a transcervical biopsy forceps.
  
  
  METHODS
  The study included CVS performed from January 1990 to March 2000 in our Unit. The results were analysed in two consecutive periods, period A (1990-1994) and period B (1995-2000), in an attempt to assess the effect of increasing experience.
  
  
  RESULTS
  Seventy-five samplings were performed in 39 multiple pregnancies, 38 twin sets and one triplet. A cytogenetic report was obtained in 73% of cases in period A and in 98% in period B. An abnormal karyotype was observed in 11 samples. The need for subsequent amniocentesis decreased from 38% in period A to 10% in period B. The spontaneous fetal loss rate in chromosomally and structurally normal fetuses before the 20th week decreased from 8.7% in period A to 3.3% in period B. The fetal loss rate after the 20th week was 3.3% in period B and none in period A. It must be noted that in three out of the four cases of fetal loss an amniocentesis was needed after CVS.
  
  
  CONCLUSIONS
  Our results suggest that effectiveness and safety improved with increasing experience. Transcervical chorionic villus sampling allows an earlier prenatal genetic diagnosis in multiple pregnancies and this may be particularly relevant for a safer selective termination when chosen by parents if one of the fetuses has an abnormal karyotype.
authors.affiliation: Prenatal Diagnosis Unit, Department of Obstetrics and Gynecology, Hospital Clínic, University of Barcelona Medical School, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Casals
authors.forename: Antoni
authors.initials: A
authors.lastname: Borrell
authors.forename: Josep M
authors.initials: JM
authors.lastname: Martínez
authors.forename: Anna
authors.initials: A
authors.lastname: Soler
authors.forename: Vicenç
authors.initials: V
authors.lastname: Cararach
authors.forename: Albert
authors.initials: A
authors.lastname: Fortuny
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000649:Amniocentesis; D002584:Cervix Uteri; D015193:Chorionic Villi Sampling / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D005260:Female; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D011247:Pregnancy; D011272:Pregnancy, Multiple; D013525:Surgical Instruments; D014427:Twins; D016216:Ultrasonography, Prenatal