Unexplained infertility: association with inherited thrombophilia

Unexplained infertility represents one of the most common diagnoses in fertility care. Attention is being paid to the association between inherited thrombophilia and infertility causes. In this study we investigated the prevalence of inherited thrombophilia according to infertility causes.

We studied Prothrombin gene G20210A mutation, Factor V Leiden, deficiencies in protein S and C and antithrombin in 930 Caucasian infertile women referred to Fertility Center of the Department of Sciences for Woman and Child's Health, University of Florence, of whom 230 with unexplained, 195 female and 283 male infertility, and in 240 women who have conceived naturally without hormonal stimulation therapy.

A significant relationship between inherited thrombophilia [OR 95%CI 1.97 (1.05-3.68), p = 0.03] and unexplained infertility was observed, whereas no association between thrombophilia and female and male infertility was found. Significantly higher prevalence of prothrombin gene mutation in unexplained infertile women in comparison to that observed in fertile women was observed (5.7% vs 2.1% p = 0.04); the prevalence of the other thrombophilia determinants was higher, even if not significantly, in the unexplained infertile group.

This study demonstrates the relationship between inherited thrombophilia and unexplained infertility, thus suggesting the contribution of genetic components in modulating unexplained infertility, behind anovulation, male and tubal factor.