title: Abnormalities in spontaneous abortions detected by G-banding and chromosomal microarray analysis (CMA) at a national reference laboratory.
abstract: BACKGROUND
  Cytogenetic evaluation of products of conception (POC) for chromosomal abnormalities is central to determining the cause of pregnancy loss. We compared the test success rates in various specimen types and the frequencies of chromosomal abnormalities detected by G-banding analysis with those found by Oligo-SNP chromosomal microarray analysis (CMA). We evaluated the benefit of CMA testing in cases of failed culture growth.
  
  
  METHODS
  Conventional cytogenetic results of 5457 consecutive POC specimens were reviewed and categorized as placental villi, fetal parts, and unspecified POC tissue. The CMA was performed on 268 cases. Of those, 32 cases had concurrent G-banding results. The remaining 236 cases included 107 cases with culture failure and 129 cases evaluated by CMA alone.
  
  
  RESULTS
  The overall POC culture success rate was 75%, with the lowest for fetal parts (37.4%) and the highest for placental villi (81%). The abnormality rate was 58% for placental villi, but only 25% for fetal parts. Of the abnormalities detected, the most common were aneuploidies, including trisomy 16, triploidy, monosomy X, trisomy 22, trisomy 21 and trisomy 15, while the least encountered aneuploidies were trisomy 1, trisomy 19 and monosomies (except monosomy 21). Overall, POC specimens studied by CMA were successful in 89.6% of cases and yielded a 44.6% abnormality rate.
  
  
  CONCLUSIONS
  Placental villi yielded higher rates of culture success and a higher percentage of abnormal karyotypes than did other specimen types. The Oligo-SNP CMA method has demonstrated a viable alternative to the G-banding method in view of its advantages in detection of submicroscopic genomic aberrations, shorter turnaround time due to elimination of time required for culture and a higher test success rate.
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Boris T
authors.initials: BT
authors.lastname: Wang
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Chong
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Fatih Z
authors.initials: FZ
authors.lastname: Boyar
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Kopita
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Leslie P
authors.initials: LP
authors.lastname: Ross
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: El-Naggar
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Trilochan
authors.initials: T
authors.lastname: Sahoo
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Jia-Chi
authors.initials: JC
authors.lastname: Wang
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Morteza
authors.initials: M
authors.lastname: Hemmat
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Mary H
authors.initials: MH
authors.lastname: Haddadin
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Renius
authors.initials: R
authors.lastname: Owen
authors.affiliation: Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, CA 92690, California.
authors.forename: Arturo L
authors.initials: AL
authors.lastname: Anguiano
keywords: CMA; G-banding; Maternal deciduous tissue; POC; Placental villi; UPD