title: First-trimester prenatal diagnosis in twin pregnancies.
abstract: Two twin pregnancies at risk for a sex-linked disorder are described. Both pregnancies were dichorionic. Transabdominal sampling was chosen for prenatal diagnosis. Molecular genetic techniques raised suspicion with regard to the accuracy of the samples in one case. Second-trimester amniocentesis confirmed the error. Selective feticide of the affected fetus was performed. When first-trimester prenatal diagnosis is offered in dichorionic twin pregnancies, confirmation through molecular genetic testing can confirm that villi have been obtained from different fetuses. All parties must be aware that additional invasive diagnostic procedures in the second trimester may be required in cases of doubt.
authors.affiliation: Department of Obstetrics and Gynaecology, University Hospital Utrecht, The Netherlands.
authors.forename: G C
authors.initials: GC
authors.lastname: Christiaens
authors.forename: J C
authors.initials: JC
authors.lastname: Oosterwijk
authors.forename: R H
authors.initials: RH
authors.lastname: Stigter
authors.forename: P P
authors.initials: PP
authors.lastname: Deutz-Terlouw
authors.forename: A L
authors.initials: AL
authors.lastname: Kneppers
authors.forename: E
authors.initials: E
authors.lastname: Bakker
mesh_terms: D000328:Adult; D015193:Chorionic Villi Sampling; D004247:DNA / Q000032:analysis; D004200:Diseases in Twins / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D009136:Muscular Dystrophies / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012730:Sex Chromosomes; D016216:Ultrasonography, Prenatal
chemical_list: D004247:DNA