Cytogenetic findings of couples with reproductive failure – retrospective analysis from Bulgarian Population

Abstract

Introduction Reproductive failure (RF) includes a variety of problems such as infertility, recurrent miscarriages, stillbirths, the birth of children with multiple birth defects, and/or mental retardation. Chromosomal aberrations in one of the partners (in 2-8%) are considered to be one of the causes of reduced fertility in couples of reproductive age. Aim The aim of this study was to evaluate the effect of the chromosomal abnormalities in families with reproductive failure (RF) in the Bulgarian population. Materials and Methods A total of 1733 patients with unexplained RF, who visited the Laboratory of Medical Genetics–Varna, Bulgaria, between January 2004 and December 2019, were investigated by conventional cytogenetic analysis GTG differential banding technique. Approximately 10 metaphases were karyotyped for each patient on the resolution 400-550 GTG bands. Results Chromosomal abnormalities were found in 110/1733 infertile patients (6.35%), and the percentage of women (4.33%) was statistically significant (p <0.0001), higher than that of men (2.02%). Most of the chromosomal abnormalities were found in patients with a combined reproductive history (40.9%, 45/110). Regarding the type of chromosomal abnormality, the structural aberrations (63.7%) were almost twice as many as the numerical (33.6%). The percentage of combined abnormalities was very low (2.72%). The numerical aberrations found by us included only sex chromosomes, and in 91.9% they were presented in a mosaic variant. Of these, 88.2% were affected females (p <0.0001). A complete form of sex chromosome aneuploidy was found in only 3 individuals, all males. Of the structural aberrations, 88.6% were in full form, of which the most common was translocation (82.3%). Conclusion RF is a socially significant problem, as the relative share of couples with reproductive disorders worldwide, as well as in Bulgaria, is constantly growing. The results of our study contribute to the detection of the causes in 6.35% of couples with RF in Bulgaria and present the undeniable benefit of conducting conventional cytogenetic analysis in such couples.