January 19, 2012
Oral Contraceptives Ease Painful Periods: Study
Results of a 30-year Scandinavian study show convincing evidence that use of combined oral contraceptive pills can help ease bloating, cramps and other painful menstrual symptoms.
Previous studies and anecdotal evidence had suggested that the combined oral contraceptive pill could have an impact on painful periods. However, a 2009 review of all the available research by the prestigious Cochrane Collaboration concluded that there was limited evidence for pain improvement.
Furthermore, while young women seem to suffer more from painful periods than older women — something confirmed in the study -- the effects of pill use and age were independent of each other, with the pill having a greater effect, the researchers said.
The researchers questioned three groups of women who reached the age of 19 in 1981, 1991 and 2001. Each group included approximately 400 to 520 women who reported their height, weight, reproductive history, pattern of menstruation and menstrual pain and contraceptive use. The women were re-assessed five years later at the age of 24.
By comparing the same women at two different ages, the researchers were able to use each woman as her own control, enabling them to establish whether any reduction in severity of symptoms was due to combined oral contraceptive (COC) use or increasing age.
"By comparing women at different ages, it was possible to demonstrate the influence of COCs on the occurrence and severity of dysmenorrhea [painful menstrual periods], at the same time taking into account possible changes due to increasing age. We found there was a significant difference in the severity of dysmenorrhea depending on whether or not the women used combined oral contraceptives,” said lead researcher Dr. Ingela Lindh at Gothenburg University in Sweden.
Pain and other symptoms were measured by two different scales: VMS (verbal multidimensional scoring system), which grades pain as none, mild, moderate or severe, and also takes into account the effect on daily activity and whether any painkillers were required; and VAS (visual analogue scale), where a woman can grade her degree of pain on a 10 centimeter line that starts with "no pain at all" and ends with "unbearable pain".
"We found that combined oral contraceptive use reduced dysmenorrhea by 0.3 units, which means that every third woman went one step down on the VMS scale, for instance from severe pain to moderate pain, and which meant that they suffered less pain, improved their working ability and there was a decrease in the need for analgesics. On the VAS scale there was a reduction in pain of nine millimeters,” Dr. Lindh said.
Independent of the effect of COC use, the researchers found that increasing age reduced the severity of dysmenorrhea, although not as much as COC did — with increasing age shifting women down 0.1 units on the VMS scale, and five millimeters on the VAS scale.
Childbirth also seemed to reduce the severity of symptoms, although this result was limited by the fact that very few women had given birth between the ages of 19 and 24.
The study also found that within the youngest group (those born in 1982), more women reported suffering from painful periods, and the severity of the symptoms was worse.
"We are unsure why this is," said Dr. Lindh.
"It may be due to changes in the type of oral contraceptive used, for example, differences in estrogen content and progestogen type, or a different appreciation of pain in the women born in later years, in that they may be more pain sensitive or are more prepared to complain about pain than women of the same age but born earlier."
Dysmenorrhea has been estimated to cause 600 million lost working hours and $2 billion dollars in lost productivity in the United States.
"Painful periods occurs frequently, particularly in young women where as many as 50-75% suffer from dysmenorrhea,” said Dr. Lindh.
“It 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. Therefore effective management of dysmenorrhea is beneficial for both the women affected and society.”
"Information about the effects of COC use on painful periods should be included in contraceptive counseling, as it has been shown that women who experience a beneficial effect of COCs other than contraception, such as a reduction in dysmenorrhea, are more likely to continue with the pill."
Combined oral contraceptive pills are currently approved for contraception by the U.S. Food and Drug Administration (FDA), but would require a randomized controlled trial to in order to include dysmenorrhea treatment as another indication for COC use.
But some doctors already prescribe COCs "off-label" to help ease painful periods.
"We are aware that drug companies have discussed with the authorities the possible design of a randomized controlled trial for the evaluation of COCs in the treatment of dysmenorrhea, but this has not yet been finalized or performed,” Dr. Lindh said.
“However, our study has clearly indicated a beneficial influence of COCs on the prevalence and severity of dysmenorrhea and the absence of a randomized controlled trial confirming this in no way reduces the value of this information."
The research was published online Wednesday in the journal Human Reproduction.
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