A longitudinal study of risk factors for the occurrence, duration and severity of menstrual cramps in a cohort of college women.

OBJECTIVE: To describe how menstrual cramps vary from cycle to cycle within a woman over time. To examine the influence of weight and lifestyle factors on occurrence, duration, and severity of menstrual pain.

DESIGN: A one-year prospective menstrual diary study.

PARTICIPANTS: One hundred and sixty-five women aged 17 to 19 years entering a local university in 1985.

MAIN OUTCOME MEASURES: The occurrence, length, and maximum severity of pain during a menstrual period.

RESULTS: Menstrual pain occurred during 71.6% of observed menstrual bleeds, most commonly beginning the first day of menses. The median duration was two days. Sixty percent of women reported at least one episode of severe pain, while 13% reported severe pain more than half the time. Earlier age at menarche and long menstrual periods increased the occurrence, duration and severity of pain. In smokers, cramps tended to last longer. Being overweight was an important risk factor for menstrual cramps and doubled the odds of having a long pain episode. Frequent alcohol consumption decreased the probability of having menstrual cramps, but in women who had pain it increased duration and severity. Physical activity was not associated with any pain parameter.

CONCLUSIONS: Women who have pain lasting three days are an important target group for prophylactic therapy. The occurrence and severity of menstrual cramps is influenced by potentially modifiable characteristics including weight, smoking, and alcohol consumption. Doctors may wish to counsel women presenting with dysmenorrhoea about the importance of healthy lifestyles and about the inefficacy of alcohol consumption as a treatment for dysmenorrhoea.