title: Prenatal diagnosis by minimally invasive first-trimester transcervical sampling is unreliable.
abstract: OBJECTIVE
  We investigated whether reliable prenatal diagnosis is possible from fetal cells harvested transcervically in first-trimester pregnancies.
  
  
  METHODS
  Fetal cells were obtained transcervically from 87 women undergoing pregnancy termination. Fetal gender was determined in 51 pregnancies with three different polymerase chain reaction techniques and in 36 pregnancies with fluorescent in situ hybridization. In known male pregnancies the number of male fetal cells present was also determined.
  
  
  RESULTS
  Polymerase chain reaction detected male deoxyribonucleic acid in up to 79% of cases in male pregnancies and up to 45% of cases in female pregnancies. Fetal gender was correctly predicted in up to 72% of cases with fluorescent in situ hybridization. However, fetal cells were identified in < 40% of informative male pregnancies and were present in low numbers-0.7% to 3.4% in swabs and 4.4% to 24.8% in flushes.
  
  
  CONCLUSIONS
  The use of fetal cells obtained by minimally invasive first-trimester transcervical sampling is unreliable for prenatal diagnosis.
authors.affiliation: Royal Postgraduate Medical School, Institute of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital, London, United Kingdom.
authors.forename: T G
authors.initials: TG
authors.lastname: Overton
authors.forename: A D
authors.initials: AD
authors.lastname: Lighten
authors.forename: N M
authors.initials: NM
authors.lastname: Fisk
authors.forename: P R
authors.initials: PR
authors.lastname: Bennett
mesh_terms: D001483:Base Sequence; D002584:Cervix Uteri; D015193:Chorionic Villi Sampling; D004247:DNA / Q000032:analysis; D005069:Evaluation Studies as Topic; D005260:Female; D005333:Fetus / Q000166:cytology* / Q000502:physiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D012680:Sensitivity and Specificity; D012732:Sex Determination Analysis
chemical_list: D015345:Oligonucleotide Probes; D004247:DNA