The Application Of G-banding And ACGH In Detecting The Karyotype Of First Trimester Spontaneous Abortions

OBJECTIVE:To investigate the incidence of chromosomal abnormalities in the first trimester spontaneous abortions and the application of array-based comparative genomic hybridization (aCGH) in analyzing the karyotype of products of conception(POC).METHODS:92spontaneous abortion specimens(chorionic villus samples) were from the gynecological outpatient service of The Shandong university affiliated provincial hospital,which was identified as "embryonic demises".Chorionic villus samples cultured in vitro and analyzed by standard G-banding techniques, cultured or G-banding failed samples were detected by aCGH.RESULTS:Karyotyping by standard G-banding techniques was attempted on92spontaneous abortion specimens,in which85specimens were analysed successfully(the success rate92.4%),7specimens that failed to yield a karyotype were detected by aCGH, the success rate of conjoint analysis by the two methods was100%.Chromosome abnormalities were found in50specimens (54.3%) a.Chromosomal abnormality rate in recurrent spontaneous abortion group and sporadic abortion group was50%and58.3%respectively, P>0.05, there was no significant statistically difference. The frequency of aneuploidy in women aged≥35years old (61.5%) was higher than that in women aged <35years old (36.4%),P<0.05,there was significant statistically difference.The sex ratio of abortus was1:1.2, The frequency of abnormal embryonic karyotypes in male abortions was less than that in female abortions,at42.9%and64.0%respectively,P<0.05,there was significant statistically difference.The abnormality rate in anembryonic gestations was53.3%, which was not statistically different from the54.8%rate seen in pregnancies with embryonic poles.When comparing miscarriages with and without a history of documented cardiac activity, there was no statistically significant difference in the rate of abnormal karyotypes,at58.7%and50% respectively,P<0.05.CONCLUSION:The major cause of the first trimester spontaneous abortions was fetal chromosome abnormalities.Chromosomal abnormalities weren’t related to number of spontaneous abortions, weren’t related to embryonic pole presence or absence nor with and without a history of documented cardiac activity assessed by ultrasound examination,but the risk increased with maternal age. We also reaffirmmed a female specific developmental disadvantage in early stages of pregnancy. ACGH has a remarkable advantage in detecting the karyotype of products of conception which failed by standard G-banding techniques.