The Effect Of Chromosomal Abnormality On Sperm Quality In Patients With Male Infertility

BackgroundAccording to data from the World Health Organization(WHO),there are about 60-80 million couples suffering from inferrtility,the number of infertility patients is growing at a speed of 2 million per year.Approximately 40%-50%of infertility were caused by male factors.The incidence of male infertility has increased quickly,which from 7%-8%in 1960s to 15%-20%in recent years.Male infertility is drawing more and more attention all over the world.Male factor infertility may give heavy psychological and economic burden not only on male parterner but also on the whole family.It is going to be a main factor for family and social unstability.However,the cause of increasing male factor infertility is still unclear.Most studies demonstrated that the increased male infertility was associated with the deterioration of global environment,the increase in the incidence of male reproductive diseases,the change of lifestyle and the bad living habits.Moreover,genetic abnormality is another important cause of male factor infertility.About 30%-40%of male factor infertility was caused by genetic defect.Karyotype is the most widely used method for genetic analysis.Abnormal karyotype would cause spermatogenesis dysfunction.However,the effect of different karyotype abnormality on semen quality and the proportion of each abnormal karyotype in patients with male factor infertility are stillunclearly.The most common abnormal karyotypes include numerical abnormalities,eg,47,XXY,47,XYY,Turner syndrome,and 48,XYYY;sex reversal,eg,46,XX male,46,XY female;chromosomal structural abnormality,eg.Roberson translocation,balanced translocation,inversion,deletion,and ring chromosome.Chromosomal polymorphismis a finding between the normality and abnormality and is still under debate,which was regarded as abnormal chromosome in this study.For infertilemale patients with confirmed abnormal karyotype,the application of assisted reproductive technology(ART)could increase the rate of pregnauncy and improve the pregnancy and neonatal outcomes.ObjectivesTo explore the necessity of chromosome abnormalty screening,and analysis the association between chromosome karyotype and sperm quality.Then through statistical analysis of the incidence and types chromosome abnormalty in male infertility patients,would provided more evidence for the etiology diagnosis,clinical management,for the male factor infertility.MethodsUsing cluster sampling,16286 patients with semen testing and karyotype analysis in a top three hospital in Jinan from July 2011 to January 2016 were selected,which concluded 10286 patients with male factor infertility and 6000 controls with a normal semen data.The clinical data and results of semenquality was collected.The original data was recorded by electronic database.The data used in this study was entrered into Epidata software by two data entry clerks.All data were analyzed by SPSS 21.0 statistical software.Categorical variables were decscribed by frequency and percentage.The difference in frequence or percentage among groups was compared by chi-square test.Continuous variables were presented by mean and standard deviation and comapred using student t test.P<0.05 was considered significant,and all statistical tests were two-sided.ResultsThe frequency of chromosome abnormalty in patients with male infertility was significantly higher than that in the non-male infertility patients(18.5%/6.2,P<0.01).Totally 1378 cases of chromosome abnormalty were uncovered.Chromosome abnormalty types with high incidence are 47,XXY(1065 cases),roberson translocation(46cases),balanced translocation(77cases),chromosome inversion(32cases),47,XYY(34 cases)and so on.Chromosomal polymorphism was found in 523 patients,including 184 patients with Yqh+,91 patients with Yqh-,65 patients with inv(9)(pl2q13),and 183 patients with other chromosomal polymorphism.In the control group,balanced translocation was found in 46 patients,chromosomal inversion in 16 patients,Roberson translocation in 18 patients,47,XY,+mar in 4 patients,and mosaism in 2 patients.Chromosomal polymorphism was found in 286 patients including 46 patients with Yqh+,2 patients with Yqh-,52 patients with inv(9)(p 12q 13),and 186 patients with other chromosomal polymorphism.1.Numerical abnormalty in sex chromosomeThe numerical abnormalty in sex chromosome only occurred in patientswithmaleinfertility.Themostfrequentkaryotypeswere47,XXY.2.Chromosome structural abnormaltyThere was no significant difference between incidence ofstructural abnormaltyin patientswith male infertility and the controlgroup(0.29%/0.03%,P=0.370).3.Chromosome polymorphismsThere was no significant difference between incidence of chromosome polymorphismsin patients with male infertility and the control roup(4.8%/1.77%.P=0.105).4.Comparison in the incidence of abnormal karyotype between the case and control groups stratified by ageIn patients<35 years,the incidence of abnormal karyotype in the case group was significantly higher than that in the control group(14.4%vs.l.51%,p<0.01).In patients?35 years,the incidence of abnormal karyotype in the case group was also significantlyhigher than that in the control group(11.3%vs 1.2%,p<0.01).5.The incidence of chromosome abnormalty in patients with different semen concentrationsInfertile patients were divided into 3 groups by different semen concentrations:normal,oligozoospermia and azoospermia.The incidence of chromosome abnormalty in azoospermia,oligozoospermia and normall-concentration patients are 19.0%(1166/6143),2.46%(102/4144)and 1.43%(86/6000)'respectively.The incidence inazoospermia patients was significantly higher than that in the other two groups(P<0.01).The incidence in oligozoospermia patientswas significantly higher than that in normal semen group(P<0.01).The incidences of chromosome polymorphisms in different groups have no significant difference(P=0.37).ConclusionsThe incidence of chromosome abnormality in thepatients with male infertility is significantly higher than that in the control group.The most common abnormal karyotype in patients with male fertility is numerical abnormlity of sex chromosome.The most common chromosomal polymorphism in the case group is Y chromosome polymorphism.