Evaluation of Chromosomal Structural Anomalies in Fertility Disorders.

Background and objectives: Reproductive disorders may occur not only due to environmental factors (air pollution, stressful lifestyle, previous abortions or the use of contraceptives) but also due to genetic factors. Materials and

Methods

The aim of the study was to identify the range and frequency of chromosomal aberrations in couples (n = 99) with infertility or recurrent miscarriages in Lithuania. The data were collected from the out-patient medical histories. The couples were divided into three groups based on pregnancy, childbirth and the number of miscarriages. The Chi-square test was used to carry out the statistical analysis, and the statistical significance was (p < 0.05).

Results

There were 6.6% (n = 13) structural changes observed in the karyotype tests. Chromosomal aberrations were found in 3% (n = 6) of the subjects, while 3.6% (n = 7) of them had chromosomal length polymorphisms. No difference was found between the aberration frequency in the karyotypes of men and women (p > 0.05). The most common aberrations were balanced translocations (23.1%, n = 3) which accounted for 15.4% of the reciprocal (n = 2) and 7.7% of the Robertsonian type (n = 1) of translocations. The most frequent aberrations were found in couples with the inability to conceive (42.9% (n = 3), p = 0.031). The childless couples and those with recurrent miscarriages showed an aberration rate of 8.2% (n = 5), while in the couples with at least one child it was 16.1% (n = 5). The group of couples unable to conceive had a significantly higher aberration rate of 28.6% (n = 2), p = 0.029. Miscarriages in partners' families accounted for 8.1%. Miscarriages on the female side of the family accounted for 4.5% (n = 9), on the male side it accounted for 2.5% (n = 5) and on both sides it accounted for 1.1% (n = 2). There were no statistically significant differences observed between the female and male sides (p > 0.05). The miscarriages observed in the second group of couples (childless with ≥2 miscarriages) were more frequent at 18.1% (n = 11), in the third group (having children ≥2 miscarriages) they were less frequent at 12.9% (n = 4), while no miscarriages were recorded in the first group of infertile couples. In total, 3% of the identified significant chromosomal aberrations were likely to trigger miscarriages or the inability to conceive.

Conclusions

In couples with reproductive disorders, chromosomal mutations and chromosomal length polymorphisms were found at similar rates: 3% vs. 3.6%. The highest aberration rate was found in couples that were unable to conceive, a lower one was found in a group with children and ≥2 miscarriages, and the lowest one was found in a childless group of subjects with ≥2 miscarriages. The miscarriage rate in partner families was 8.1%; however, no difference was found between the male and female sides.