A prospective study on the association between red hair color and endometriosis in infertile patients

OBJECTIVE: To determine if red-haired infertile women have an increased prevalence of endometriosis. DESIGN: Prospective, nonblinded. SETTING: Large, metropolitan, private hospital, associated with a university. Subspeciality care provided by reproductive endocrinologists. PATIENTS: One hundred forty-three consecutive women undergoing laparoscopy or laparotomy for infertility. INTERVENTIONS: Laser ablation of any endometriosis present. MAIN OUTCOME MEASURE: Presence of endometriosis. RESULTS: Of 143 women entered into the study, 12 had natural red hair. The ages of these women ranged between 23 and 41 years. Ten of 12 (83%) of the red-haired women were found to have endometriosis compared with 55 of 131 (42%) of nonredheads. By statistical analysis, the 95% confidence intervals for the presence of endometriosis in redheads was 55% to 100% versus 34% to 51% for nonredheads. CONCLUSION: The results suggest an association between the occurrence of natural red hair and those factors that lead to the development of endometriosis.