Dietary habits, reproductive and menstrual factors and risk of dysmenorrhoea.

In order to analyze risk factors for dysmenorrhoea, we conducted a case-control study. Cases were 106 women (median age 27 years) with moderate or severe dysmenorrhoea lasting 12 months or more. Controls were 145 women (median age 26 years) without dysmenorrhoea, admitted for routine gynecological examination at the outpatient gynecological services of the same clinic where cases had been identified. In comparison with women reporting short menstrual cycles (every 25 days or less) the relative risk (RR) of dysmenorrhoea was 2.0 and 2.6, respectively, in those reporting their menstrual cycles of 26-30 days and of 31 days or more, and the RR was 3.6 (95% confidence interval (CI): 1.0-13.4) for women reporting totally irregular menstrual cycles. The estimated RRs were, in comparison with women reporting menstrual flows lasting 4 days or less, respectively 2.2 and 1.9 in those reporting menstrual flows lasting 5 and 6 days or more. Fourty-four (58%) cases but only seven (5%) controls reported heavy menstrual flows (RR in comparison with women reporting slight or normal menstrual flow 12.6, 95% CI: 5.0-32.1). As regards dietary factors, no associations emerged between the various food items, with the exception of cheese and eggs, which tended to be more frequently consumed by cases than controls. The results of this study suggest that the risk of dysmenorrhoea is higher in women with irregular, long and heavy menstrual flows. No association emerged between reproductive history and dysmenorrhoea. Likewise, no clear relationship emerged between intake of several dietary factors and risk dysmenorrhoea.