Reflex fluorescent in situ hybridization testing for unsuccessful product of conception cultures: A retrospective analysis of 5555 samples attempted by conventional cytogenetics and fluorescent in situ hybridization

Abstract

Introduction:The use of chromosome analysis on products of conception from spontaneous abortions is recommended to identify a genetic etiology. However, 20% of products of conception cultures are unsuccessful due to microbial contamination or lack of viable dividing cells. Our laboratory implemented a reflex fluorescent in situ hybridization (FISH) assay to detect numeric chromosome abnormalities for unsuccessful cultures. Materials and Methods: All products of conception samples were simultaneously processed for both chromosome analysis and FISH analysis. If the chromosome analysis was unsuccessful, interphase FISH was performed for chromosomes 13,16,18,21,22, X, and Y. To assess the performance of the FISH assay, a 3-year retrospective comparative analysis of the FISH results versus chromosome results was performed. Results: Of 5555 total specimens, 4189 (75%) represented chorionic villi/fetal tissue and 1366 (25%) represented tissue of unidentified origin. Of the 1189 tissues of unidentified origin with chromosome or FISH results, 1096 (92%) were XX, indicating that the majority of these tissues are likely maternal in origin. Of the 3361 successful chromosome studies on the chorionic villi/fetal tissue specimens, 1734 (52%) samples had a chromosome abnormality. Of the 762 successful FISH studies on chorionic villi/fetal tissue specimens that were unsuccessful by chromosome studies, 181 (25%) had an abnormal result with the targeted FISH panel. Overall, the FISH panel detected approximately 70% of the chromosome abnormalities in products of conception detectable by karyotype. When the FISH panel results were combined with chromosome analysis for the 4189 chorionic villi/fetal tissue specimens, the overall abnormality rate is 47%. Conclusions: Our reflex FISH assay proved useful for the detection of common chromosome aneuploidies in products of conception samples that failed conventional chromosome analysis. Because of its limited view of the genome, cautious interpretation of FISH results is required for all samples, in particular, trisomy of an acrocentric chromosome, which may represent a Robertsonian translocation. An algorithmic approach to the genetic evaluation of products of conception specimens, with the potential for initial evaluation by a FISH panel, may be warranted. Genet Med 2011:13(6):545-552.

Overview of Chromosome Abnormalities in First Trimester Miscarriages: A Series of 1,011 Consecutive Chorionic Villi Sample Karyotypes

“…We obtained a 90.3% rate of successful chromosome analysis, which is higher than the rates reported in some of the previous large studies that performed cytogenetic ( Table 6 ) [Eiben et al, 1990;Menasha et al, 2005;Shearer et al, 2011;Jenderny, 2014;Wang et al, 2014]. Our success rate is similar to the 92.4% rate obtained in the recent study of Sahoo et al [2017] using mostly SNP-array analysis in fresh tissue samples, but lower than the 99.9% rate reported by Levy et al [2014], although in this case 22% of the samples were not valid due to maternal cell contamination.…”

Comprehensive genetic analysis of pregnancy loss by chromosomal microarrays: outcomes, benefits, and challenges

“…Whole-chromosome aneuploidies are the most common etiology. [4][5][6][7][8][9][10][11] Fetal chromosomal abnormalities account for approximately 8-10% of intrauterine fetal demises occurring after 20 weeks of gestation and/or stillbirths occurring in the second or third trimester. 9,12 The etiologic analysis of pregnancy loss can provide important information for medical management, reproductive counseling, and supportive patient care.…”

“…9,[15][16][17][18][19] Additionally, the quality and viability of POC samples are critical for successful cell culture and karyotype analysis. 4,8 Second, even when tissue is dissected carefully, there is always the risk of an erroneous result due to maternal cell contamination (MCC). Specifically, selective overgrowth of maternal cells during culture can result in a normal female karyotype even in the presence of an underlying fetal chromosome abnormality.…”

Correlation analysis between ultrasound findings and abnormal karyotypes in the embryos from early pregnancy loss after in vitro fertilization-embryo transfer

“…Few articles have evaluated the correlation between an anembryonic sac and chromosomal abnormalities, and their results were inconsistent [2,3,5,29] (Table 3). Our study found that the risk of chromosomal abnormality with this type of ultrasound finding was not significantly higher than the risk associated with other abnormal ultrasound findings.…”

“…Over 95 % of miscarriages occur in the first trimester, and more than half of spontaneous miscarriages result from chromosomal abnormalities, mostly aneuploidies [2][3][4]. Of these, the most common abnormalities are autosomal trisomies (60 %), followed by monosomy X (20 %) and polyploidy (20 %) [5,6].…”