Large sample analysis of chromosome karyotypes in couples with poor fertility history

Objective To analyze the detection rate of abnormal chromosome karyotypes and distribution of abnormal karyotypes of couples with poor fertility history, and to explore the relationship between abnormal chromosomal karyotypes and infertility, and to provide theoretical basis for genetic problems in eugenics. Methods A total of 10 330 pairs (20 660 cases) of childbearing couples with poor fertility history who received detection of chromosome karyotypes at Jinan Adicon Clinical Laboratories from January 1, 2016 to December 31, 2017 were selected as research subjects. And 3 mL elbow venous blood of each subject was collected and anticoagulated with heparin sodium. Then, 0.3 mL venous blood was selected for cell culture and specimen preparation. Routine G-band technique was used for chromosomal karyotype analysis. For the detection rate of abnormal chromosome karyotypes, and the proportion of different types of abnormal chromosome karyotypes in total abnormal chromosome karyotypes, etc. were expressed by rate (%). The procedures followed in this study were in line with the requirement of World Medical Association Declaration of Helsinki revised in 2013. Results ①Among the 10 330 pairs (20 660 cases) of childbearing couples with poor fertility history, 1 119 cases of abnormal chromosome karyotypes were detected (excluding chromosome polymorphism), and the detection rate was 5.42% (1 119/20 660). There were 658 cases of autosomal abnormalities, accounting for 58.80% (658/1 119) of total abnormal karyotypes, which included 354 cases of chromosome balance translocations, 205 cases of chromosome inversions, 83 cases of chromosome Robertsonian translocations, 11 cases of chromosome insertions, and 5 cases of chromosome duplication, respectively, accounting for 31.64%, 18.32%, 7.41%, 0.98% and 0.45% of total abnormal karyotypes, respectively. Most of the subjects with chromosome inversions were characterized by spontaneous abortions, and most of the inversional chromosomes were inverted on chromosome 9, and occasionally on chromosomes 1, 4, 7, 11, and 12. There were 440 cases of sex chromosome abnormalities, accounting for 39.32% (440/1 119) of total abnormal karyotypes. Among them, number of abnormal sex chromosomes occurred in 365 cases (accounting for 32.62% of total abnormal karyotypes), of which males were mostly characterized by azoospermia and 47, XXY abnormality, and most of the females were characterized by primary infertility and 45, X abnormality. There were 61 cases of sex chromosome structural abnormalities (accounting for 5.45% of total abnormal karyotypes), 14 cases of sexual reversal (accounting for 1.25% of total abnormal karyotypes). There were 21 cases of other rare abnormal chromosome karyotypes, accounting for 1.88% (21/1 119) of total abnormal karyotypes, such as circular chromosomes and mar chromosomes. ②Among the 10 330 pairs (20 660 cases) of childbearing couples with abnormal fertility history, there were 11 cases of autosomal insertion abnormal karyotypes, 5 cases of autosomal duplication abnormal karyotypes, 54 cases of sex chromosome deletion, and their main clinical manifestations were primary infertility, embryonic losses, azoospermia or severe oligozoospermia. Conclusions Abnormal chromosome karyotypes are one of the most important causes of poor fertility of childbearing couples. For childbearing couples with poor fertility history, karyotype analysis and genetic counseling are recommended. Clinically, the guidance of prenatal and postnatal care for such patients can improve the quality of birth population. Key words: Chromosome aberrations; Sex chromosome aberrations; Sex chromosome disorders of sex development; Reproductive history, abnormal; Karyotype analysis; Genetic counseling; Prepotency and postnatal care; Childbearing couples