EPIDEMIOLOGY OF ENDOMETRIOSIS AMONG PAROUS WOMEN

Objective: To report the prevalence of endometriosis and its associate d risk factors among multiparous women, and to determine the relations hip between the location and depth of this disease and certain medical and behavioral characteristics. Methods: Over a 6-year period, 3384 m ultiparous women underwent laparoscopy for tubal sterilization. Endome triosis was detected in 126 patients (3.7%), who were consequently eva luated for severity of the disease. To conduct a case-control study, 5 04 patients with no evidence of endometriosis were randomly selected f rom a group of women who underwent sterilization. Information obtained through physical examination and a self-administered questionnaire wa s studied by multivariate logistic regression analysis. Results: Most endometriosis lesions were minimal. Factors associated with an increas ed risk for endometriosis included: advanced age (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.1-3.7), Asian race (OR 8.6, 95% CI 1.4 -20.1), long cycle length (OR 1.8, 95% CI 1.1-2.7), one live birth (OR 2.2, 95% CI 1.1-4.3), long duration of intrauterine device use (OR 3. 0, 95% CI 1.1-8.1), and long duration of uninterrupted menstrual cycle s (OR 2.9, 95% CI 1.3-6.4). Present oral contraceptive use was protect ive for disease (OR 0.5, 95% CI 0.2-0.9). The role of these factors va ried among different disease locations (ovary, uterus and tubes, poste rior broad ligaments and cul-de-sac), and depth (superficial or deep). Conclusions: The prevalence of endometriosis is relatively low among multiparous women, and certain menstrual and reproductive characterist ics are associated with its development. Furthermore, the relationship between various factors and endometriosis appears to be site and dept h specific. Our findings suggest that asymptomatic endometriosis may b e clinically important.