title: Chorionic villus sampling: experience with an initial 940 cases.
abstract: Of over 1000 patients referred to the Genetics & IVF Institute for chorionic villus sampling, 10% had an abnormal gestational sac at the time of initial presentation. Villus sampling could not be performed in 0.6% of cases, usually because of fibroids. Chorioamnionitis, probably related to the procedure, occurred in two patients (0.2%). The total fetal loss was 2.4%, which is not significantly different from the background fetal loss rate reported in normal pregnancies after eight weeks of gestation. The procedure-related loss was estimated as approximately 0.6%. The cytogenetic analysis routinely used was "direct" trophoblast karyotyping. There were no false-negative diagnoses. Trophoblastic mosaicism was observed in 1.3% of samples. Amniocentesis was performed in 3.5% of cases because of chorionic villus sampling failure, chorionic mosaicism, or elevated maternal serum alpha-fetoprotein (MSAFP) concentrations. Chorionic villus sampling was not associated with falsely elevated MSAFP levels at 15-18 weeks' gestation. Chorionic villus sampling has proved a safe and accurate prenatal diagnostic method associated with relatively low risk when performed by an experienced team, although additional amniocentesis will be necessary in a small percentage of pregnancies.
authors.affiliation: Genetics & IVF Institute, Fairfax, Virginia.
authors.forename: J E
authors.initials: JE
authors.lastname: Green
authors.forename: A
authors.initials: A
authors.lastname: Dorfmann
authors.forename: S L
authors.initials: SL
authors.lastname: Jones
authors.forename: S
authors.initials: S
authors.lastname: Bender
authors.forename: L
authors.initials: L
authors.lastname: Patton
authors.forename: J D
authors.initials: JD
authors.lastname: Schulman
mesh_terms: D000328:Adult; D001706:Biopsy; D002824:Chorionic Villi / Q000648:ultrastructure*; D002869:Chromosome Aberrations / Q000175:diagnosis; D025063:Chromosome Disorders; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D030342:Genetic Diseases, Inborn / Q000175:diagnosis; D006801:Humans; D007621:Karyotyping; D008661:Metabolism, Inborn Errors / Q000175:diagnosis; D011247:Pregnancy; D011296:Prenatal Diagnosis