Approximately, 50% of first-trimester miscarriages have chromosomal abnormalities which can be detected by conventional cytogenetic analysis. The presence of chromosomal abnormality may explain the cause of miscarriage, improving the reproductive counseling and planning.

Purpose To study meiotic segregation patterns of Robertsonian translocations in sperm of male carriers and to assess the frequencies of unbalanced sperm formation. Methods FISH with combination of probes to detect all the variants of meiotic segregation was performed on decondensed sperm nuclei of 5 carriers of der(13;14), 3 carriers of der(14;21) and one carrier of a rare der(13;21) translocation. Results The frequency of sperm with alternate segregation and normal/balanced chromosomal complement ranged from 68 % to 94.4 % (mean 79.2±8.4). Adjacent segregation was detected in 17.9±7.3 % of sperm (from 5.6 % to 29 %). No significant differences in frequencies of gametes with nullisomies and disomies of chromosomes involved in translocations were observed. The mean frequency of 3:0 segregation products was 2.5±1.4 %. Conclusions All analyzed patients showed homogenous segregation pattern with clear predominance of alternate segregation resulting in normal/balanced sperm production. Still, from 5.8-32 % (mean 20.4±8.3 %) of sperm was unbalanced, which is the evidence of the increased risk of unbalanced offspring in carriers of Robertsonian translocations. Our results highlight the importance of genetic counseling of Robertsonian translocation carriers prior to ICSI or IVF.

Purpose To assess the frequency and types of chromosomal abnormalities in 204 Ukrainian patients with non-obstructive azoospermia and oligozoospermia and 87 men with normozoospermia. Methods Cytogenetic studies were performed on peripheral blood lymphocyte samples of 164 men with oligozoospermia, 40 men with non-obstructive azoospermia and 87 men with normozoospermia attending infertility clinic. Results Chromosomal abnormalities were detected in 17 % of patients with sperm disorders: in 35 % of men with azoospermia and in 12.7 % of men with oligozoospermia. The frequency of chromosomal abnormalities in patients with sperm disorders was significantly higher, than in patients with normozoospermia (P=0.0001). An increase in the incidence of chromosomal abnormalities with the decrease of sperm count was observed. Chromosomal abnormalities were detected in 1.1 % of patients with normozoospermia, 6.5 % of patients with mild oligozoospermia (sperm count 5-15 ×10 6 /ml), 18.4 % of patients with severe oligozoospermia (sperm count <5 ×10 6 /ml) and 35 % of patients with azoospermia. A significant increase in the frequency of chromosomal abnormalities in patients with severe oligozoospermia was observed when compared to mild oligozoospermia (P=0.01). A statistically significant association (P= 0.02) of chromosomal abnormalities and sex chromosome abnormalities (P=0.0001) with azoospermia when compared to oligozoospermia was observed. Conclusions Our results highlight the importance of cytogenetic studies in patients with oligozoospermia (both mild and severe) and non-obstructive azoospermia. The presence of chromosomal abnormalities influences significantly the fertility treatment protocols, as well as provides a definite diagnosis to couples suffering from infertility.

The results of cytogenetic studies of 3414 patients with infertility (1741 women and 1673 men) were analyzed retrospectively to estimate the frequency and types of chromosomal abnormalities in infertile patients. Chromosomal abnormalities were detected in 2.37% of cases (81/3414), corresponding to an abnor mality frequency of 2.79% among men and 1.95% among women. Balanced structural chromosomal rear rangements were predominant in the studied group, constituting 80.2% of all chromosomal abnormalities. Gonosomal abnormalities comprised 23.5% of the detected chromosomal pathology (19/81) and were pre sented by gonosomal aneuploidies in 84% of cases (16/19) and structural rearrangements of chromosome Y in 16% of cases (3/19). The frequency of sex chromosome low level mosaicism was 0.55%. Our results high light the importance of cytogenetic studies in patients with infertility before the start of infertility treatment programs with assisted reproduction techniques, since the detection of chromosomal abnormalities makes it possible to identify infertility etiology as well as change the treatment approaches.