Secondary Dysmenorrhoea

Secondary dysmenorrhoea is painful menstruation caused by pelvic disease, including endometriosis, adenomyosis, fibroids, pelvic inflammatory disease, copper intrauterine device, cervical stenosis and obstructive uterine or vaginal anomalies. It usually begins after age 25 years or years after the periods have been painless, tends to get worse with time, and often occurs with heavy bleeding, dyspareunia or infertility. It matters because it identifies treatable disease that may harm fertility if missed.

• Risk factors: endometriosis, previous pelvic infection, nulliparity, intrauterine device, previous pelvic surgery, family history, congenital anomalies.
• Pain may begin before bleeding and last through the period.
• Endometriosis is a common cause.

Women have pelvic pain that starts days before the period and lasts throughout, with deep dyspareunia, chronic pelvic pain, heavy menstrual bleeding, painful bowel movements or urination during periods, and subfertility. Examination may show a tender fixed uterus, nodules in the uterosacral ligaments or an adnexal mass.

• Tender uterus or nodularity on pelvic examination.
• Pain not relieved by NSAIDs alone.
• Differential diagnosis: endometriosis, adenomyosis, fibroids, pelvic inflammatory disease, chronic endometritis, intrauterine device pain, cervical stenosis, congenital outflow obstruction, ovarian cyst, pelvic adhesions, interstitial cystitis, irritable bowel syndrome, pelvic congestion.
• Complications: infertility, chronic pelvic pain, ovarian endometrioma, tubo ovarian abscess, anaemia, depression, bowel or urinary tract involvement.

The approach is imaging and, where needed, laparoscopy to find the cause.

• History of onset, relation to bleeding, dyspareunia, bowel and bladder symptoms, infection risk and contraception; pelvic examination.
• Transvaginal ultrasound (endometrioma, fibroids, adenomyosis with heterogeneous myometrium); MRI for deep endometriosis or anomalies.
• Chlamydia and gonorrhoea tests, high vaginal swab, full blood count, C-reactive protein; urine hCG.
• Diagnostic laparoscopy with biopsy for suspected endometriosis; hysteroscopy for cavity lesions or cervical stenosis.

The principle is analgesia with hormonal suppression, and treatment of the cause, including surgery.

• Supportive: heat; exercise; pelvic physiotherapy; psychological support; pain and menstrual diary; treatment of partner for infection.
• Pharmacological: ibuprofen 400 mg oral 8-hourly with food for 3 to 5 days during pain, or mefenamic acid 500 mg oral 8-hourly with food for 3 to 5 days; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); endometriosis or adenomyosis: dienogest 2 mg oral once daily for 6 months or longer, or norethisterone acetate 5 mg oral once daily increased to 15 mg daily, or combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms oral once daily taken continuously, or levonorgestrel intrauterine system 52 mg for 5 years; severe disease: leuprorelin 3.75 mg IM every 4 weeks for up to 6 months with tibolone 2.5 mg oral once daily as add back; pelvic inflammatory disease: ceftriaxone 1 g IM once, then doxycycline 100 mg oral 12-hourly plus metronidazole 400 mg oral 12-hourly for 14 days; chronic endometritis: doxycycline 100 mg oral 12-hourly for 14 days; fibroids: tranexamic acid 1 g oral 8-hourly for 4 days during bleeding.
• Procedures: laparoscopic excision or ablation of endometriosis and adhesions; cystectomy for endometrioma; hysteroscopic removal of polyps or fibroids; cervical dilatation for stenosis; incision of a vaginal septum or imperforate hymen; uterine artery embolisation or myomectomy for fibroids; hysterectomy for adenomyosis or disease resistant to treatment when childbearing is complete.
• Special groups: women wishing to conceive have surgery or fertility treatment instead of hormonal suppression; adolescents with severe pain have ultrasound for obstructive anomalies and early laparoscopy if pain persists on treatment; women with an intrauterine device and severe pain have removal and infection excluded.
• Red flags: fever with pelvic pain, adnexal mass, severe pain with vomiting or collapse, pain with positive pregnancy test, haematuria or rectal bleeding with periods, no response to 3 months of treatment.
• Follow-up: review at 3 months with pain score; ultrasound after 6 months for endometrioma; review of fertility plans; surgical referral if pain persists.