The association of dysmenorrhea with noncyclic pelvic pain accounting for psychological factors

Abstract

Objective: The factors that underlie pelvic pain are poorly understood. Specifically, the relative influence of dysmenorrhea and psychological factors in the etiology of noncyclic pelvic pain conditions, such as interstitial cystitis and irritable bowel syndrome, is unknown. To further characterize pelvic pain, we compared the frequency of menstrual, somatosensory, and psychological risk factors between women with and without severe noncyclic pelvic pain symptoms.

Study design: A total of 1012 reproductive-aged women completed a 112-item questionnaire with domains including mood, fatigue, physical activity, somatic complaint, and pain. Questionnaire items included existing items for menstrual distress and newly written items derived from qualitative interviews. The relationship of dysmenorrhea and noncyclic pelvic pain complaints (dyspareunia, dyschezia, or dysuria) was modeled using quantile regression.

Results: Among women who menstruate regularly, those with dysmenorrhea had disproportionally more severe noncyclic pelvic pain (54/402, 13%) than women without dysmenorrhea (5/432, 1%; odds ratio, 13; 95% confidence interval, 5-33). In a multivariate-adjusted model, dysmenorrhea (β = .17), activity capability (β = .17), somatic complaint (β = .17), and bodily pain (β = .12) were the primary predictors of noncyclic pelvic pain. Depression (β = .03) and anxiety (β = .01) were not significantly predictive. The presence of dysmenorrhea, somatic complaint, and low activity capability predicted 90% of the cases of women with noncyclic pelvic pain.

Conclusion: The association between dysmenorrhea and noncyclic pelvic pain suggests that menstrual pain is an etiological factor in noncyclic pelvic pain, whereas depression and anxiety may be secondary effects. Longitudinal studies are needed to determine whether dysmenorrhea causally influences development of noncyclic pelvic pain or shares common underlying neural mechanisms.

Keywords: dysmenorrhea; interstitial cystitis; irritable bowel syndrome; pelvic pain.

FIGURE 1. Relationship of pelvic pain to dysmenorrhea

Box and whiskers plots indicate median, upper/lower decile, and upper/lower quartile for noncyclic pelvic pain constructs in subjects categorized with differing levels of menstrual pain (indicated by color and y axis). Related, but less specific constructs (abdominal, pelvic, and overall pain) also were correlated to severity of dysmenorrhea.

FIGURE 2. Binned scatter plot of combined model of hypothesized factors involved in noncyclic pelvic pain

Number of subjects with given noncyclic pelvic pain percentile score (x axis) is shown by diameter of each circle. Output of model based on amount of somatic complaint, activity capability, bodily pain, and dysmenorrhea is shown on y axis. Cluster of subjects has no noncyclic pelvic pain (left) and is predicted to have below median noncyclic pelvic pain. Above median levels of noncyclic pelvic pain, linear correlation between actual noncyclic pelvic pain and predicted noncyclic pelvic pain is shown by line generated by locally weighted scatter plot smoothed regression.