Dysmenorrhoea and heavy menstrual bleeding — formative SAQs

SAQ 1 — Primary vs secondary dysmenorrhoea and the management ladder (20 marks, ~15 minutes)

A 15-year-old presents with painful periods that began about a year after menarche. The pain is midline, cramping, starts just before menses, lasts two days, and recurs predictably. An ibuprofen trial helped partially. She is not sexually active. Her mother is concerned the pain "has been worse the last three cycles" and wonders whether it is "just normal period pain." ^[1]

Questions

1. Define dysmenorrhoea, classify this presentation as primary or secondary, and justify your classification from the history. State when primary dysmenorrhoea typically begins and why. (5 marks) ^[1]
2. Give the stepwise management ladder for dysmenorrhoea with agent, dose, route, timing and rationale, and cite the supporting evidence. (6 marks) ^{[5] [6]}
3. List the history features that would reweight the assessment toward secondary dysmenorrhoea, and name the leading secondary cause in the adolescent. (5 marks) ^[1]
4. Describe how you would frame the consultation, including the role of seeing the young person alone and integrating the menstrual cycle as a vital sign. (4 marks) ^[2]

Model answer (must-hit)

1. Dysmenorrhoea is cyclic pelvic pain with menstruation. This is primary dysmenorrhoea: the pain is midline, cramping, cyclic and predictable, began about a year after menarche, and has no red-flag features. Primary dysmenorrhoea begins only once ovulatory cycles establish, typically 6 to 12 months after menarche, because the secretory-phase progesterone of an ovulatory cycle primes the endometrium to synthesise prostaglandins and leukotrienes — the mediators of the pain. It does not start from the very first period. ^[1]
2. The ladder: first, an NSAID at the onset of menses — ibuprofen 400 to 600 mg or naproxen 250 to 500 mg, with food, for 2 to 3 days of bleeding — because NSAIDs block prostaglandin synthesis and are more effective than placebo (Marjoribanks 2010, Cochrane). Second, the combined oral contraceptive if the NSAID is inadequate or contraception is desired, assessed over three cycles at an adequate dose; the oral contraceptive pill improves dysmenorrhoea over placebo (Wong 2009, Cochrane). Third, review adherence and reconsider a secondary cause. Fourth, refer for pelvic ultrasound and gynaecology. ^{[5] [6]}
3. Features that point to secondary dysmenorrhoea: pain not relieved by NSAIDs and the combined oral contraceptive; non-cyclic pain; chronic pelvic pain between periods; dyspareunia; dyschezia; GI/GU symptoms; and activity- or school-limiting pain out of proportion to a normal period. The leading secondary cause in the adolescent is endometriosis, which carries a long diagnostic delay. An obstructive Müllerian anomaly, pelvic infection, and an intrauterine device are the other secondary causes. ^[1]
4. Frame confidentiality up front with its limits, and see the young person alone so the sexual and psychosocial history can be taken completely; the menstrual assessment sits inside the HEEADSSS framework. Treat the menstrual cycle as a vital sign — an irregular or absent cycle is a signal of an eating disorder, over-training, or thyroid disease, not a nuisance. The recent worsening is explored, but the baseline pattern fits primary dysmenorrhoea. ^[2]