In the United States, painful periods (Dysmenorrhoea) are estimated to cause 600 million lost working hours and cost two billion dollars in lost productivity. A large Scandinavian study published online in Europe’s leading reproductive medicine journal Human Reproduction, has finally provided compelling evidence, after running for 30 years, that the combined oral contraceptive pill does indeed relieve symptoms of painful menstrual periods, known as dysmenorrhoea.
Even though a few earlier studies and unscientific evidence have indicated that the combined oral contraceptive pill is likely to have an impact on painful periods, the prestigious Cochrane Collaboration concluded in a 2009 review of all research available that the evidence to improve pain remained limited.
The new study by Dr Ingela Lindh and her team, at the Institute of Clinical Sciences, Sahlgrenska Academy at Gothenburg University in Sweden, demonstrates that those women using a combined oral contraceptive pill experienced less severe pain than those who did not use it. The researchers noted that compared with older women, those of a younger age often appeared to experience more painful periods and that the symptoms lessened as the women’s age increased. However, they note that the effects of using the pill, and age, were independent of each other, with the pill showing the stronger effect.
The researchers surveyed three groups of women, each group including about 400 to 520 women, who reached 19 years of age in 1981, 1991 and 2001, with a follow-up five years later when they reached the age of 24 year. The women were asked to report statistics on their weight, height, menstruation pattern, reproductive history, menstrual pain, and use of contraceptive.
Given that the same women were compared at two different ages, the researchers could use each woman as her own control. This enabled them to find out whether any reduction in severity of symptoms was due to an increase in age or by using combined oral contraceptive (COC).
Dr Lindh, a registered nurse and midwife, explained: “By comparing women at different ages, it was possible to demonstrate the influence of COCs on the occurrence and severity of dysmenorrhoea, at the same time taking into account possible changes due to increasing age. We found there was a significant difference in the severity of dysmenorrhoea depending on whether or not the women used combined oral contraceptives.”
The researchers measured pain levels and other symptoms by using the VMS and the VAS scale. The VMS, or verbal multidimensional scoring system, classifies pain levels as ‘none’, ‘mild’, ‘moderate’ or ‘severe’ and also accounts for effects on daily activity, as well as whether any painkillers were required. The VAS, or visual analogue scale, allows women to describe their pain level on a 10 cm line that begins with ‘no pain at all’ and ends with “unbearable pain”.
“We found that combined oral contraceptive use reduced dysmenorrhoea 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,” states Dr Lindh.
The researchers also discovered independently of the effect of COC use that increasing age lowered the severity of dysmenorrhoea, yet not to the same degree as COC. The results displayed that women’s pain levels were shifted down by 0.1 units on the VMS scale, and five millimeters on the VAS scale. They also observed that childbirth appeared to reduce the severity of symptoms, however, this result was limited given that only few women had given birth between the ages of 19 and 24 years.
Furthermore, the researchers discovered that those in the youngest group, who were born in 1982, reported experiencing painful periods with a worse severity of the symptoms. Dr. Lindh commented: ”We are unsure why this is. 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.”
She added:
“Painful periods occurs frequently, particularly in young women where as many as 50-75% suffer from dysmenorrhoea. 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 dysmenorrhoea 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 dysmenorrhoea, are more likely to continue with the pill.”
The combined oral contraceptive pill is currently approved for contraception by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). In order to include dysmenorrhoea treatment as another indication for COC use, the regulatory authorities would require a randomized controlled trial, although some doctors already prescribe COC “off-label” to help patients with painful periods.
Dr Lindh concluded: “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 dysmenorrhoea but this has not yet been finalized or performed. However, our study has clearly indicated a beneficial influence of COCs on the prevalence and severity of dysmenorrhoea and the absence of a randomized controlled trial confirming this in no way reduces the value of this information.”
Written by Petra Rattue