The role of estrogens on moles biology remains undefined although estrogenic receptors have been found on melanocytes. It has been postulated that supraphysiological estrogen levels could promote the progression of moles to melanoma. Women undergoing controlled ovarian stimulation (COS) for assisted reproductive technologies (ART) are exposed to high levels of estrogens, produced by the ovary in response to exogenous gonadotropin administration. The aim of this study is to assess whether COS for ART may have an impact on mole structure and/or characteristics.