[Subfertility phenotype, chromosome polymorphism and conception failures]

To evaluate the prevalence of cytogenetic alterations and chromosomic polymorphism in couples with a subfertility phenotype in a Brazilian population.

Karyotype analysis through G and C banding of 1,236 individuals who presented the subfertility phenotype, from two different centers (public and private) were included in the study. These patients were classified in two sub-groups: one with two or more gestational consecutive losses or not and the o with, at least, one gestacional loss or absence of conception. Karyotype results were evaluated in different groups and frequencies were calculated. Statistical analyses were carried out through Fisher's exact test and Odds Ratio analysis.

Approximately 25% of the cases presented abnormal karyotype results, including numerical and structural alterations and also polymorphic variants. In both centers, the prevalence of polymorphic variants was 8.9 and 3.8%, respectively.

There was no significant difference between the prevalence of polymorphic variants and other abnormalities in individuals with or without previous history of reproductive loss. The results of the present study reinforce the need of adequate disclosure of complete cytogenetic information in the karyotype results, with specific attention in relation to the polymorphic variants.