Premenstrual spotting of ≥2 days is strongly associated with histologically confirmed endometriosis in women with infertility.

OBJECTIVE The purpose of this study was to assess the prevalence of endometriosis in women with premenstrual spotting and to determine the predictive value of this symptom in the diagnosis of endometriosis. STUDY DESIGN We conducted a retrospective cohort study of 80 consecutive women who presented to the infertility clinic for evaluation and who subsequently underwent laparoscopic assessment for infertility with or without pelvic pain. Our main outcome measure was the presence or absence of histologically confirmed endometriosis in women with and without premenstrual spotting. RESULTS Endometriosis was significantly more prevalent in subfertile women who reported premenstrual spotting for ≥2 days relative to women without this symptom (89% [34/38 women] vs 26% [11/42 women]; P < .0001). Multinomial logistic regression analysis demonstrated the presence of premenstrual spotting for ≥2 days to be associated significantly with the presence of endometriosis (odds ratio, 16; 95% confidence interval, 3.9-65.4; P < .01) and red vesicular lesion type (odds ratio, 52.6; 95% confidence interval, 8.6-323.1; P < .001). CONCLUSION In this cohort of women with infertility, premenstrual spotting of ≥2 days was associated strongly with histologically confirmed endometriosis and a better predictor than dysmenorrhea or dyspareunia of finding endometriosis at laparoscopy. Premenstrual spotting of at least 2 days was also associated strongly with both higher stage disease and the red vesicular peritoneal endometriosis phenotype.