| Background:Spontaneous abortion is defined as the loss of the conceptus before22weeks of gestation when fetal weight is less than500g. It is the most frequent complication of a pregnancy. Several etiologies of spontaneous abortion have been proposed on the basis of available data, that have varied from genetic, anatomical, immunology, infections, endocrine and environental factors, among which the genetic etiology accounts for more than two third of SA. At present, the chromosome aberrations offetal is the most common known etiology of spontaneous abortion.Chorionic villus has the same genetic traits with embryos. Therefore, villous chromosomal detection is one of the important ways to detection the reason of spontaneous abortion. Cytogenetic analysis of spontaneous abortion products provides valuable information on the frequency of chromosomal abnormalities in various ethnic groups, their etiology, the risk of recurrence and the suspicion of a mutagenic activity in a population. At present,the traditional cytogenetic method is by cell culture and G-banding technology. Although the karyotype is very sensitive for detecting autosomal trisomies and aneuploidy affecting sex chromosomes, which represent the most common fetal chromosome abnormalities. However, the karyotype has some limitations, like its lower solution and the requirement of cell culture. Which is worse, G-banding can’t diagnosis the marker chromosomes and the complex chromosomal structure aberrations because of its low resolution. Fluorescence in situ hybridization(FISH) depends on the strong molecular biology techniques, which do not require cell culturing before analysis and may be performed automatically and has more advantages than G-banding. FISH are simple, rapid and sensitive tools for the detection of chromosomal aneuploidies. Avoiding the cell culture step necessary for karyotyping, they represent very interesting alternative methods to diagnose genomic disorders in products of abortion in which poor sample quality often leads to cell culture failure. Which is better, FISH achieving results faster and at lower cost. It also could detect of a plurality of chromosome number abnormality at the same time, had a great clinical application value.Embryo chromosomal abnormality is the most important reason of early embryo development arrest. Analysis the detection rate and the types of abnormal karyotype in chorionic villus of spontaneous abortion timely, we can find the reason of spontaneous abortion, and get more useful prognostic information and to guide the next pregnancy.Objective:The aim of this study was to highlight the most common chromosomal karyotype causes of fetal loss in chorionic villus of abortion products or in utero fetal death cases by using FISH technology and conventional karyotype analysis. The two kinds of detection results were compared together. To explore the values of conventional karyotype analysis and assess the values of FISH in the detection. Studying the correlation between the patient’s age, gestational weeks of spontaneous abortion and other factors to further interpret the aetiology of spontaneous abortion.Methods:The research was conducted by retrospective analysis of the data between August2010and October2013in the Center for Reproductive Medicine, Provincial Hospital Affiliated to Shandong University and inpatient579cases of spontaneous abortion in pregnant women, in a suitable manner of termination of pregnancy.449cases of chorionic villus using the long-time culture method to culture cells and do karyotype analysis by G-banding.228cases of chorionic villus were detected the number of13,16,18,21,22, X, Y chromosome by FISH and related data analysis. The clinical data of all cases were recorded a retrospective review.Results:(1) Conventional karyotype analysis was attempted on449chorionic villus.311cases there was either no growth in culture or contaminated. The success rate is only30.73%, among which there were17chromosomal abnormalities, the abnormal ratio was12.32%;(2)86cases were abnormal detected by FISH technology of228cases, the abnormal ratio was37.72%;204cases are the useful samples which have the records of different pregnancy:the number of the samples distribution in early pregnancy(less than12weeks), middle pregnancy(12-23weeks) were196cases,8cases, each accounted for96.08%and3.92%; Trisomy of chromosome had the highest incidence of53.49%(46/86) among, followed by12cases of triploid(13.95%) and5cases monosomy X (5.81%);(3)There were14cases using conventional karyotype analysis and the FISH technology, only4cases of which are different in the two ways. The concordance rate is71.43%;(4) Recurrent spontaneous abortion group has a higher abnormal ratio of44.19%than the first spontaneous abortion group which is only34.38%. With the increasing number of abortions, the abnormal ratio of villi chromosome was increased, but the difference was not statistically; The abnormal chromosome karyotype rate of IVF group was31.36%, less than44.44%of ICSI group, but no statistical difference was found between the abnormal rate.Conclusions:(1)Embryo chromosomal abnormality is the most important reason of spontaneous abortion, it is necessary to make karyotype analysis in chorionic villus when the woman has spontaneous abortion;(2) Trisomy of chromosome had the highest incidence among chromosomal abnormalities, followed by triploid and monosomy X;(3)Cell culture and G-banding technology is the traditional cytogenetic method of karyotyping. However, it has the limitation in gaining the success in culture of chorionic villus and recognizing the complex chromosomal structure aberrations because of its low resolution;(4)There were characteristic of rapid, simple, high-specificity by FISH technology, it is a more efficient tool of identify chromosomal abnormality in chorionic villus of spontaneous abortion;(5)With the increasing number of abortions, the abnormal ratio of the chorionic villus was increased, but the difference was not statistically; With different ART, the chromosome abnormal rate of chorionic villus of spontaneous abortion have no significant difference. |
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