Natural progression of menstrual pain in nulliparous women at reproductive age: an observational study.

BACKGROUND Menstrual pain can be alleviated after childbirth. The purpose of this observational study was to evaluate the natural progression of menstrual pain among nulliparous women at their reproductive age. METHODS A questionnaire-based study of perimenopausal women with a history of primary dysmenorrhea was performed. The study subjects were recruited between July 1, 2001 and June 30, 2005. Severity of menstrual pain was graded using a multidimensional scoring system. RESULTS A total of 247 nulliparous women with primary dysmenorrhea were enrolled, and of these, 218 patients were eligible for analysis. Patients who had more frequent intercourse (p = 0.016), fewer associated systemic symptoms (p = 0.028), and use of oral contraceptive pills (p = 0.039) tended to have a higher chance of an improvement in dysmenorrhea after age 40. Multidimensional scoring distribution over chronologic age revealed that patients had significantly improved menstrual pain after 40 years of age. CONCLUSION For nulliparous women with primary dysmenorrhea, the severity of menstrual pain decreased significantly after age 40. More studies are needed to explore this phenomenon from a biochemical or molecular basis.