The correlation between the frequency of sister-chromatid exchange and human reproductive hormones

Different frequencies of sister-chromatid exchanges (SCEs) during various stages of the menstrual cycle have previously been observed. We tested the hypothesis that sex hormones, particularly steroids, influence the frequency of SCEs in women undergoing ovulation induction for in vitro fertilization treatment. These women undergo extreme hormonal changes and therefore serve as a good model for testing the rate of genetic damage due to these changes. As controls, we tested fertile women with regular menstrual cycles who received no hormonal treatment. Peripheral lymphocytes were obtained during different stages of the normal and treated cycles. We examined SCE frequency as related to the different hormones of the reproductive cycle at each of the stages. In general, an increased SCE frequency was observed around ovulation time in the controls, and around the time of human chorionic gonadotropin administration in the group undergoing ovulation induction. However, in the latter group, SCE frequency was significantly higher. SCE frequency was positively correlated with the level of testosterone and FSH in the ovulation induction group, and positively correlated with the estradiol level in both groups.