title: Reliability of trans-cervical recovery of placental cells from the lower uterine pole using a minimally invasive procedure. Evidence based on fetal sexing and analysis of recovered cell populations.
abstract: OBJECTIVE
  Efficient recovery of placental cells (and their subsequent characterisation) from the lower uterine pole (L.U.P) by trans-cervical flushing or aspiration.
  
  
  METHODS
  Women attending for termination of pregnancy (7-17 weeks' gestation) for social reasons. All patients gave their consent to the procedures outlined below.
  
  
  METHODS
  Trans-cervical intrauterine flushing (using 0.15 M NaCl) or mucus aspiration. Embryo transfer catheters were used in both procedures. Fetal sexing was achieved by gene amplification of Y-specific DNA sequences (Y-PCR), and by in situ hybridisation (bright-field and fluorescence) to the Y-chromosome. Data were compared with results obtained from fetal tissues recovered following termination of pregnancy. Gender-independent tests for fetal cells utilised immunocytochemistry with trophoblast-specific antibodies and dual immunocytochemistry/ISH, where appropriate.
  
  
  RESULTS
  (1) Fetal sexing by Y-PCR: 71/122 (58%) aspirates contained Y-specific DNA. In addition, the sexing of 72/86 (84%) aspirates and their corresponding samples of placental tissue, agreed exactly. (2) Microscopic detection of fetal cells. Placentally-derived syncytiotrophoblast was detected in 17/45 (38%) flushings and 39/173 (23%) aspirates. In most other Y-PCR+ samples which were negative for syncytiotrophoblast, Y-chromosome-bearing nuclei of unknown origin, were observed by ISH and immunocytochemical evidence for cytotrophoblastic cells was also uncovered.
  
  
  CONCLUSIONS
  Since Y-derived DNA can be detected in > 50% of flushings and aspirations, and gender-independent evidence for placental cells was obtained, regardless of fetal sex, we believe that most or all of these samples contained placental cells, including trophoblasts and naked nuclei. Trans-cervical placental cell recovery is a potentially valuable alternative to more invasive methods of aneuploid detection which require amniocentesis and CVS, provided its level of accuracy and above all, safety, can be evaluated.
authors.affiliation: Division of Obstetrics and Gynaecology, University of Leeds, Leeds General Infirmary, UK.
authors.forename: D
authors.initials: D
authors.lastname: Miller
authors.forename: J
authors.initials: J
authors.lastname: Briggs
mesh_terms: D002584:Cervix Uteri; D004247:DNA / Q000032:analysis; D005260:Female; D006801:Humans; D010920:Placenta / Q000166:cytology*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D012732:Sex Determination Analysis; D013396:Suction; D007507:Therapeutic Irrigation; D014998:Y Chromosome
chemical_list: D004247:DNA