The Necessity Of Chromosome Analysis Among Infertile Couples Undergoing IVF Or ICSI

Constitutional aberrant karyotypes can account for infertility or recurrent pregnancy loss. The rate of chromosomal anomaly in the general population is0.5%-0.85%; while in the infertile population, it is as high as1.97%-14.3%.With the development of human reproduction technology, concern about a possible increase in the rate of early miscarriages or fetal malformations owing to parental genetic anomalies has increased. For those couples carrying chromosomal aberrations detected before IVF/ICSI, preimplantation genetic diagnosis (PGD) or prenatal diagnosis technology is available for them to reduce abortion or fetal malformation.Several studies have reported an increased frequency of chromosomal abnormalities, not only in men with a fertility problem but also in the female partner in couples undergoing IVF or intracytoplasmic sperm injection (ICSI). Many articles have been written on frequency of chromosomal aberrations in males who are candidates for ICSI, whereas very few data are available regarding the frequency in couples undergoing other techniques, such as IVF. In this study, we intended to analyze the frequency of chromosomal abnormalities in couples who were referred to our medical center with an indication for either IVF or ICSI. The present study offers our contribution on the topic by a retrospective analysis of the prevalence of chromosomal abnormalities in a population of infertile Chinese couples attending assisted reproduction programs.ObjectiveTo explore that it is necessary to routinely detect chromosomes in fertile couples, we analyzed the prevalence of aberrant karyotypes of infertile couples referred for IVF or ICSI living in East China.MethodClinical files of9973infertile patients receiving karyotype analysis (male:2857female:7116), referred during October2012to October2013to receive treatment by either IVF or ICSI were reviewed in this study. Differences between proportions were assessed by x2-test (SAS9.2P<0.05).ResultThe prevalence of chromosomal anomaly was significantly higher in infertile couples than general populations (259/99732.60%vs.0.85%P<0.0001). The prevalence of chromosomal anomaly among2857males and7116females were both significantly higher than general populations (6.02%vs.0.85%P<0.0001;1.22%vs.0.85%P<0.0001respectively), and the prevalence between female and male was significantly different (P<0.0001). The prevalence of chromosomal polymorphism was also significantly higher in infertile couples than general populations(8.84%vs.1.77%,P<0.0001),and the difference between female and male was statistically significant (10.47%vs.8.14%P=0.0002).Among259chromosomal abnormalities, the most common aberrations were reciprocal balanced translocations (96),Klinefelter’s syndrome (55),Robertsonian translocations (45) inversion (15),deletions (8),46, XX reversal male (7),47, XYY (6)1. Structural chromosome aberrationsThe incidence of structural chromosome aberrations was5.3times higher than in newborns (1.64%vs0.31%P<0.0001). The incidence in women and men was respectively12.6and3.3times higher than in newborns:the increase was significantly different between these two groups (3.22%vs.1.01%P<0.0001).The prevalence of reciprocal balanced translocations(0.96%vs.0.14%P<0.0001), Robertsonian translocations(0.45%vs.0.12%P<0.0001),deletions(0.08%vs.0.01%P=0.0002),inversion(0.15%vs.0.03%P<0.0001) were all significantly higher than the general population.2. Non-mosaic numerical gonosomal aberrations and46, XX reversal male In infertile males, the prevalences of Klinefelter’s syndrome(1.89%vs.0.173%P <0.0001) and46, XX reversal male (7/28570.24%vs.0.01%P<0.0001) were both significantly higher than those general population., while the prevalence of XYY syndrome was comparable (0.245%vs.0.118%P=0.08).In infertile females, Turner syndrome(0.01%vs.0.053%P=0.177)and Triple-X syndrome (0.03%vs.0.106%P=0.0561) were both comparable between infertile couples and those general population.3. Chromosome abnormalities were related to the sperm count;70anomalies were detected in344non-obstructive azoospermia(20.3%);33in622severe oligozoospermia(5.47%);23in mild oligozoospermia(6.9%);45anomalies in1095normal men (4.1%). The prevalence of karyotype changes is significantly higher in non-obstructive azoospermia group. No chromosomal anomalies were detected in463patients with obstructive azoospermia.4. Prevalence of karyotype changes among women with a different history of spontaneous abortion showed some significant differences. In the group of female partners, the prevalences of chromosomal aberrations were both significantly higher among the women with spontaneous abortion≥1history(36/8734.12%vs.0.85%P<0.0001)、spontaneous abortion=1(13/6341.98%vs.0.85%P=0.0019)、spontaneous abortion≥2(23/21610.6%vs.0.85%P<0.0001)in comparison to those general population, while the prevalence was comparable among the women without spontaneous abortion history (51/62430.82%vs.0.85%P=0.3611)in comparison to those general population.5. Prevalence of karyotype changes between primary infertility group and secondary infertility group. In the group of female partners the prevalence of chromosomal aberrations was significantly higher among the women with secondary infertility in comparison to those with primary infertility(1.9%vs.0.67%P<0.0001). However, in the group of male partners the prevalence was significantly higher among the men with primary infertility in comparison to those with secondary infertility(6.66%vs.4.57%P<0.0001).Conclusion 1. Infertile couples requiring IVF or ICSI treatment appeared to be affected by higher frequency of chromosomal abnormalities than the general population.2. Categories with greater risk were represented by men with azoospermia or primary infertility, and women with history of pregnancy loss or secondary infertility, especially among those women with more than twice spontaneous abortion.3. Routine chromosome analysis prior to IVF or ICSI treatment is necessary and it can be able to discover aberrant karyotypes early, which could provide guidance to the intervention of corresponding assisted reproductive techniques, such as PGD or prenatal diagnosis.