The authors of another study that involved 70 patients with endometriosis did not find any significant relationships between the basal prolactin serum levels and stage of endometriosis or the outcome of the infertility treatment, but even this study reported a significantly greater prolactin response after 500 micrograms of TRH injection in the patients who did not become pregnant than those who did [11]. This evidence concerns the gene PRL and Infertility.