title: Reliability of 46,XX results on miscarriage specimens: a review of 1,222 first-trimester miscarriage specimens.
abstract: OBJECTIVE
  To examine the rate of maternal contamination in miscarriage specimens.
  
  
  METHODS
  Retrospective review of 1,222 miscarriage specimens submitted for chromosome testing with detection of maternal cell contamination (MCC).
  
  
  METHODS
  Referral centers requesting genetic testing of miscarriage specimens at a single reference laboratory.
  
  
  METHODS
  Women with pregnancy loss who desire complete chromosome analysis of the pregnancy tissue.
  
  
  METHODS
  Analysis of miscarriage specimens using single-nucleotide polymorphism (SNP) microarray technology with bioinformatics program to detect maternal cell contamination.
  
  
  METHODS
  Chromosome content of miscarriages and incidence of 46,XX results due to MCC.
  
  
  RESULTS
  Of the 1,222 samples analyzed, 592 had numeric chromosomal abnormalities, and 630 were normal 46,XX or 46,XY (456 and 187, respectively). In 269 of the 46,XX specimens, MCC with no embryonic component was found. With the exclusion of maternal 46,XX results, the chromosomal abnormality rate increased from 48% to 62%, and the ratio for XX to XY results dropped from 2.6 to 1.0.
  
  
  CONCLUSIONS
  Over half of the normal 46,XX results in miscarriage specimens were due to MCC. The use of SNPs in MCC testing allows for precise identification of chromosomal abnormalities in miscarriage as well as MCC, improving the accuracy of products of conception testing.
authors.affiliation: Stanford Hospital and Clinics, Obstetrics and Gynecology-Reproductive Endocrinology and Infertility, Stanford University, Palo Alto, California. Electronic address: rlathi@stanford.edu.
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Lathi
authors.affiliation: Stanford Hospital and Clinics, Obstetrics and Gynecology-Reproductive Endocrinology and Infertility, Stanford University, Palo Alto, California.
authors.forename: Stephanie L F
authors.initials: SL
authors.lastname: Gustin
authors.affiliation: Natera, Inc., San Carlos, California.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Keller
authors.affiliation: Natera, Inc., San Carlos, California.
authors.forename: Melissa K
authors.initials: MK
authors.lastname: Maisenbacher
authors.affiliation: Natera, Inc., San Carlos, California.
authors.forename: Styrmir
authors.initials: S
authors.lastname: Sigurjonsson
authors.affiliation: Natera, Inc., San Carlos, California.
authors.forename: Rosina
authors.initials: R
authors.lastname: Tao
authors.affiliation: Natera, Inc., San Carlos, California.
authors.forename: Zach
authors.initials: Z
authors.lastname: Demko
mesh_terms: D058489:46, XX Disorders of Sex Development / Q000175:diagnosis* / Q000235:genetics*; D000022:Abortion, Spontaneous / Q000175:diagnosis* / Q000235:genetics*; D000328:Adult; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000235:genetics*; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: 46,XX; aneuploidy; karyotype; maternal cell contamination; miscarriage; products of conception