Sex During Menses Increases Endometriosis and Infertility: 498 female patients were interviewed. Endometriosis and tubal infertility factor were diagnosed on laparoscopy or laparotomy. The frequency of endometriosis was higher (P less than .05) in patients with coitus during menses (17.5%) than in women never having sex during menses (10.9%). The frequency of PID was not different. The frequency of tubal infertility factors was higher in the PID group (78.4%) than in the non-PID group (30.4%) (P less than .001). Endometriosis was associated with an increase in tubal infertility factors (47.9% vs. 33.3% in the nonendometriosis group) but to a lesser degree than PID. Coitus during menses. Its effect on endometriosis and pelvic inflammatory disease. Filer RB, Wu CH. Thomas Jefferson University. J Reprod Med. 1989 Nov;34(11):887-90

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