Villus Chromosome Analysis Of Missed Abortion In Pregnant Women Of Different Age Groups

ObjectiveTo observe the incidence of villus chromosomal abnormalities in 158 cases of missed abortion patients at various ages,analyze the law of villus chromosome abnormalities with the age of pregnant women,and explore the relationship between missed abortion and villus chromosome abnormalities of pregnant women in different age groups.DesignChose patients who were treated in the People's Hospital of Rizhao from January2017 to December 2019,aged 20-47 years old,with an average age of 33.06 ± 7.18 years old.Among them,58 had missed abortion in their first pregnancy,53 had a history of spontaneous abortion of less than 2 times,and 89 were multiparas who had conceived and delivered a healthy fetus.Inclusion and exclusion criteria: single pregnancy in utero,the gestational age ranges from 7 to 15 weeks.,embryo or fetus without fetal heart pulsation,retention in the uterine cavity,which is not discharged in time;non-recurrent miscarriage;the patient voluntarily requests a villus chromosome test;patients who request the examination of villus chromosomes are negative in TORCH serum,vaginal secretions,chlamydia and mycoplasma;have not used prohibited or cautioned drugs since pregnancy;no history of addiction to tobacco and alcohol,exposure to radiation and toxic substances;no uterine anatomical abnormalities;exclude patients with history of basic diseases.A total of 158 cases of missed abortions were included.Villus specimens were examined using bacterial artificial chromosome-on-beads(BoBs).Examination range: examination of abnormal chromosome numbers 1 to 22,X,Y(aneuploidy),missing long arm or short arm within the coverage of the probe,which has a hint to some polyploidy.The 158 patients were divided into three age groups of <35,35-40,and >40,and the statistical analysis of villus chromosomes karyotype was performed.Analyzed the abnormal karyotype of villus chromosomes in each age group,and the probability of villus chromosome abnormality in each age group.The collected data was analyzed and processed using SPSS 25.0 software.ResultsOf the 158 villus specimens,64 cases(40.51%)of normal karyotypes and 94 cases(59.49%)of abnormal karyotypes were detected.Among the abnormal karyotypes,there were 78 cases of aneuploidy trisomy(accounting for 82.98% of the total number of abnormalities),15 cases of monomers(accounting for 15.96% of the total number of abnormalities)and 1 case of chimera(accounting for 1.06% of the total number ofabnormalities).Of the 98 cases younger than 35,there are 50 cases of chromosomal abnormalities(accounting for 51.02% of the age group);of the 43 cases between the ages of 35 and 40,there are 24 cases of chromosomal abnormalities(accounting for 70.59% of the age group);of the 26 cases older than 40,there are 20 cases of chromosomal abnormalities(accounting for 76.92% of this age group).For the missed abortion patients older than 35 years old,the probability of villus chromosomal abnormalities increased significantly.The ratio of chromosome number abnormality karyotypes in the <35 age group was lower than that in the 35-40 age group and the >40 age group,and the difference between the groups was statistically significant(P = 0.019).The chi-square test did not reach statistical significance in the chromosomal abnormality rate between the35-40 age group and the >40 age group(P = 0.582).Aneuploidy monomers can be seen in the <35 age group,and are rare in the ?35 age group.The abnormal karyotypes are ordered by detection rate from high to low as: 22,16,X,15,21 and 20.These karyotypes account for 64.89% of the total abnormal karyotypes detections.X monomer was more common in the younger group,and the incidence rate decreased with the mother's age.Trisomy 22,15,21 and 20 were more common in the elderly group,and the incidence rate increased with the age of pregnant women.Conclusion1.Women of advanced maternal age will bear a higher risk of chromosomal abnormalities in embryos.The detection rate of the abnormal karyotypes in the >40 age group is slightly higher than that in the 35-40 age group.2.The rate of abnormal chromosomes 15,20,21 and 22 increases with the age of pregnant women.Among them,the detection rate of trisomy 22 varies significantly with age(P = 0.003).The incidence rate of X monomer decreases with the age of the mother.3.The probability of villus chromosome abnormality in women of advanced maternal age with missed abortion is extremely high.Therefore,based on the results of villus chromosome examination,further analysis for genetic counseling and eugenic guidance should be done.