Birth control pills relieve pain associated with menstruation, a 30-year Swedish study found.
The research, published Tuesday in the journal Human Reproduction, studied women over a 30-year period to confirm whether combination oral contraception pills do indeed alleviate symptoms of painful menstrual periods, known as dysmenorrhea.
Researchers surveyed three groups of hundreds women who reached 19 years of age in 1981, 1991 and 2001. The women were then assessed again, five years later, at the age of 24. Birth control pills proved to reduce pain more than age.
"By comparing women at different ages, it was possible to demonstrate the influence of [combined oral contraception] on the occurrence and severity of dysmenorrhea, at the same time taking into account possible changes due to increasing age," Ingela Lindh of the Institute of Clinical Sciences at Gothenburg University in Sweden, said in a statement. "We found there was a significant difference in the severity of dysmenorrhea depending on whether or not the women used combined oral contraceptives."
Most gynecologists have believed in the pill's pain relieving properties for decades, but a review published in the Cochrane Collaboration in 2009 concluded that there was only limited evidence to suggest the pain relief benefits.
"Gynecologists have been prescribing combined oral contraceptives for the last 40 years and for this indication," said Dr. Paula Hillard, professor of obstetrics and gynecology at Stanford University School of Medicine. "It was disappointing to see results of Cochrane. ... But gynecologists didn't feel that this proved that the pills weren't helpful, only that the studies hadn't yet been done to show it."
The study authors reported that dysmenorrhea accounts for 600 million hours lost at work and $2 billion worth of productivity in the United States alone.
"[Painful periods] can have a detrimental effect on these women's lives, causing regular absenteeism from school and work, and interfering with their daily activities for several days each month," lead author Lindh continued in the statement. "Therefore effective management of dysmenorrhea is beneficial for both the women affected and society."
And experts welcome the confirmed findings.
"This is a well-done, informative study," said Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at the University of Missouri-Kansas City. "The evidence is finally available to support what physicians see in their offices on a daily basis -- women with painful menses are indeed helped by being on a combined estrogen/progesterone pill to make the menses lighter and less painful in discharge."