title: The diagnostic performance of cytogenetic investigation in amniotic fluid cells and chorionic villi.
abstract: First-trimester chorionic villus sampling has not reached the popularity of second-trimester amniocentesis in prenatal cytogenetic diagnosis, in contrast to initial expectations. We investigated whether a difference in the diagnostic performances of cytogenetic investigation in amniotic fluid (AF) cells and chorionic villi in favour of AF-cells might justify this. Diagnostic performance was measured as laboratory failure rate, karyotype quality (G-band score, rate of follow-up samples, rate of wrong diagnoses), and karyotype representativity (rate of follow-up samples, rate of wrong diagnoses). From 1993-1999, 11 883 AF-samples were investigated (AF-cells). In chorionic villi, short term culture preparations solely were karyotyped from 1993-1996 (n=3499) (STC-villi), short and long-term culture preparations simultaneously provided a sufficient amount of tissue being available from 1997 onwards (n=1829) ((STC+LTC)-villi). Laboratory failure rates were the same after amniocentesis (0.40%) and chorionic villus sampling (0.50%). G-band scores (mean+/-SD) were equal in AF-cells (373+/-38.1) and LTC-villi (364+/-32.6) but significantly lower in STC-villi (311+/-34.6) (p=0.001). Follow-up sampling rates because of quality reasons were the same in AF-cells (0.14%), STC- villi (0.13%) and (STC+LTC)-villi (0.11%). Two wrong diagnoses turned up among AF-cells. Follow-up sampling rates because of representativity reasons differed significantly between AF-cells (0.10%), (STC+LTC)-villi (1.31%), and STC-villi (1.99%) (p<0.001). However, the ratios of the total numbers of follow-up samples and uncertain or abnormal cytogenetic results in STC, and (STC+LTC)-villi at cytogenetic risks > or =3% (0.132 and 0.160, respectively) were equal to that in AF-cells at risks <3% (0.155). Two wrong diagnoses were made in STC-villi. Diagnostic performance improved in the rank order of STC-villi, (STC+LTC)-villi and AF-cells. At cytogenetic risks > or =3%, (STC+LTC)-villi showed a diagnostic performance equal to that in AF-cells. This might justify a selective use of chorionic villus sampling.
authors.affiliation: Department of Clinical Genetics, University Hospital Dijkzigt, Erasmus University, Rotterdam, The Netherlands. Los@kgen.fgg.eur.nl
authors.forename: F J
authors.initials: FJ
authors.lastname: Los
authors.forename: C
authors.initials: C
authors.lastname: van Den Berg
authors.forename: H I
authors.initials: HI
authors.lastname: Wildschut
authors.forename: H
authors.initials: H
authors.lastname: Brandenburg
authors.forename: N S
authors.initials: NS
authors.lastname: den Hollander
authors.forename: E M
authors.initials: EM
authors.lastname: Schoonderwaldt
authors.forename: L
authors.initials: L
authors.lastname: Pijpers
authors.forename: R
authors.initials: R
authors.lastname: Jan H  Galjaard
authors.forename: D
authors.initials: D
authors.lastname: Van Opstal
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000166:cytology; D002478:Cells, Cultured; D002824:Chorionic Villi; D015193:Chorionic Villi Sampling; D002869:Chromosome Aberrations; D020732:Cytogenetic Analysis; D003951:Diagnostic Errors; D005260:Female; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D011247:Pregnancy