Young women can experience significant dysmenorrhoea in the first years after menarche, which may have a considerable negative effect on their ability to attend school and participate in other activities. While the prevalence of adolescent dysmenorrhoea is hard to quantify, it has been reported to affect 60–70 per cent of young women, with up to 15 per cent stating that it interferes with daily activities. School absenteeism and inability to participate in extracurricular activities are frequently reported by young women with dysmenorrhoea. The majority of adolescents with painful periods experience primary dysmenorrhoea, with structural genital tract anomalies and endometriosis accounting for approximately 10 per cent of cases of adolescent dysmenorrhoea.¹

Characteristics of primary dysmenorrhoea

Primary dysmenorrhoea typically presents 6–24 months post-menarche with a predictable pattern, starting prior to or with menses, lasting up to 72 hours, sometimes with associated symptoms such as headache, breast tenderness, diarrhoea, nausea or vomiting. After menarche, it takes on average 1–2 years (though may take up to five years) for the hypothalamic-pituitary-ovarian axis to mature, resulting in regular, ovulatory menstrual cycles. In general, a later onset of menarche is associated with a longer period of time before cycles are ovulatory. Primary dysmenorrhoea is believed to arise from high concentrations of uterine prostaglandins, which are produced as part of the process to precipitate sloughing of the endometrium, resulting in increased myometrial contractility, followed by ischaemia and hypoxia of the myometrium, causing pain. The decline in progesterone levels in the luteal phase also contributes to elevated prostaglandin levels via the arachidonic acid cascade.²

Diagnosis

In adolescents, a careful history alone is usually sufficient to establish the diagnosis of primary dysmenorrhoea and to initiate treatment. Ultrasound scans are frequently performed in the primary care setting and can provide reassurance that the uterus is structurally normal. However, increased anxiety can be caused by the finding of ‘polycystic ovaries’ on ultrasound scans in adolescents. While not the focus of this article, diagnostic criteria for polycystic ovaries in adolescents differ from those in adult women, and the finding of multicystic ovaries in the adolescent is entirely normal. Other differential diagnoses include ovarian cysts and non-gynaecological conditions, such as inflammatory bowel disease, irritable bowel syndrome and painful bladder syndrome; although a cyclical pattern of pain is most typical of primary dysmenorrhoea.

Management approach

First-line treatment of adolescent dysmenorrhoea is to commence the combined oral contraceptive pill (COCP), with the addition of non-steroidal analgesia. Cyclical use of the COCP can reduce dysmenorrhoea by a reduction in prostaglandin load through suppression of ovulation and by lessening myometrium contractility through reduced menstrual flow. Continuous use of the COCP may be first-line management in the setting of significant dysmenorrhoea. When starting the COCP in adolescents, a 30μg pill (for example, Levlen ED, Microgynon 30, Ava 30 ED) is recommended. A withdrawal bleed should be scheduled at the end of the first pill packet, followed by continuous use of the active pills. The pill can be taken continuously until breakthrough bleeding occurs, or a withdrawal bleed can be scheduled at the patient’s convenience. A four-day hormone pill break is sufficient to allow for a full withdrawal bleed.³

Non-steroidal anti-inflammatory drugs (NSAIDs), such as mefanamic acid, should be commenced 2–3 days prior to withdrawal bleeds, as they can act to lower circulating prostaglandin levels and also reduce menstrual flow by up to 30 per cent.¹ Tranexamic acid may result in a reduction of menstrual loss of up to 50 per cent, so can be used in conjunction with other NSAIDS for dysmenorrhoea primarily related to heavy menstrual flow. The pattern of pain in this setting is often different to dysmenorrhoea related to prostaglandins, as pain correlates with the days of heaviest flow, (for example, days 1–3) rather than premenstrually when the prostaglandin load is highest. Other prostaglandin-related symptoms, such as nausea, diarrhoea and dizziness, may be absent where pain is primarily related to heavy flow.

The aim of continuous COCP use is to achieve amenorrhoea with resulting improvement and resolution of primary dysmenorrhoea. The pill dose can be increased to 35 or 50μg of ethinyl oestradiol (Brevinor, Brevinor-1, Microgynon 50) with supplementary oral progesterone, if needed.

The levonorgestrel-releasing intrauterine system (Mirena) can be offered for management of adolescent dysmenorrhoea when oestrogen is contraindicated or poorly tolerated. An ultrasound scan to measure the length of the endometrial cavity is not required as a standard-sized Mirena can be safely used in any uterus post-menarche, regardless of age. The Mirena is effective for the treatment of dysmenorrhoea through menstrual suppression, resulting in amenorrhoea or a reduction in menstrual loss of at least 90 per cent by 12 months post-insertion. Insertion in a young woman who is not yet sexually active is performed under general anaesthetic or sedation.

Laparoscopy can be considered if there is ongoing pain with significant impact on quality of life, particularly school attendance and participation in extracurricular activities, but this should ideally be deferred until at least six months of amenorrhoea is achieved.
The reason for this is twofold:

1. To ensure an adequate trial of menstrual suppression.
2. To have a plan for hormonal suppression post-laparoscopy if endometriosis is discovered.

Secondary dysmenorrhoea (for example, due to endometriosis) is much less common than primary dysmenorrhoea in adolescents. Experience from a tertiary paediatric and adolescent gynaecology service has shown that of a cohort of adolescents presenting with dysmenorrhoea, 90 per cent received first-line treatment with the COCP. Of the 8 per cent that underwent laparoscopy for ongoing pain, two thirds had no pelvic pathology identified. Ten- to 15-year follow-up data showed no increase in rates of endometriosis and no impact on fertility compared with controls.⁴ While laparoscopy is minimally invasive, it does carry risks.

Chronic pelvic pain

Our understanding of pain sensitivity in women with dysmenorrhoea continues to evolve. Persistent dysmenorrhoea may result in central sensitisation, typically demonstrated as hypersensitivity to pain. Menstrual suppression, combined with use of non-steroidal analgesia, aims to reduce the noxious stimulation of the central nervous system and reduce the risk of developing central sensitisation. The approach to chronic pelvic pain is multidisciplinary, with a combination of hormonal menstrual suppression, pain modulator medication, physiotherapy and psychology. Repeated laparoscopies should be avoided in this setting.

Conclusion

First-line treatment for adolescent dysmenorrhoea should be medical rather than surgical, with a focus on improvement in quality of life. This is most readily achieved with hormonal menstrual suppression and the use of non-steroidal analgesia.

1. Sanfilippo J, Erb T. Evaluation and management of dysmenorrhea in adolescents. Clin Obstet Gynecol. 2008;51(2):257-67.
2. Iacovides S, Avidon I, Baker FC. What we know about primary dysmenorrhea today: a critical review. Hum Reprod Update. 2015;21(6):762-78.
3. Oral contraceptives – Skipping periods when taking the pill. RCH Kids Health Info. Available from: www.rch.org.au/kidsinfo/fact_sheets/Oral_Contraceptives__Skipping_periods_when_taking_the_Pill.
4. Grover S. The Dysmenorrhoea Study. Presentation – FIGO Conference. 2015. Vancouver, Canada.