Menorrhagia (Heavy Menstrual Bleeding)

Definition

"Excessive menstrual bleeding that interferes with a woman's physical, emotional, social, and quality of life - deemed excessive by the patient regardless of duration, frequency, or timing."

Classification of Causes - PALM-COEIN

Causes by Age Group

• In adolescents, up to 24% with menorrhagia may have an underlying bleeding disorder - most commonly von Willebrand disease - Textbook of Family Medicine 9e
• Primary coagulation disorders account for up to 20% of acute uterine bleeding in adolescents - Tintinalli's Emergency Medicine

Pathophysiology

1. Structural causes - fibroids (especially submucosal), polyps, malignancy, or adenomyosis physically disrupt normal endometrial shedding and hemostasis.
2. Dysfunctional uterine bleeding - the most common type, where there is no structural abnormality. Usually caused by anovulation, which leads to unopposed estrogen stimulation of the endometrium. Most common at menarche and perimenopause due to HPO axis instability. Other causes include:
   • Endocrine disorders (prolactinoma, thyroid disease)
   • PCOS or ovarian tumors (granulosa cell tumors)
   • Obesity, malnutrition, or chronic systemic illness
   • Luteal phase defect (insufficient progesterone from corpus luteum)

Clinical Features

• Soaking through pads/tampons frequently (e.g., every 1-2 hours)
• Passing large clots (>1 cm)
• Periods lasting >7 days
• Symptoms of iron deficiency anemia: fatigue, pallor, dyspnoea
• Impact on daily activities, work, and quality of life

Investigations

• Full blood count - to assess for anemia
• Coagulation screen / von Willebrand studies - especially in adolescents
• Thyroid function tests
• Pelvic ultrasound - first-line imaging to identify structural causes
• Hysteroscopy + endometrial biopsy - for women >45 years, or if malignancy is suspected
• Pregnancy test - always exclude pregnancy first

Management

• Levonorgestrel-releasing IUD (Mirena) - most effective medical treatment; reduces blood loss by 80-90%
• Tranexamic acid - antifibrinolytic; reduces menstrual blood loss, including from fibroids
• NSAIDs (e.g., mefenamic acid) - reduce blood loss ~30% and help with dysmenorrhoea
• Combined oral contraceptives - regulate cycles and reduce flow
• Progestogens (oral or depot) - suppress endometrial proliferation
• GnRH analogues - for fibroids or as pre-surgical treatment (recent meta-analyses confirm GnRH antagonists are effective for fibroid-related HMB - PMID 39821450)

• Endometrial ablation (e.g., NovaSure system) - destroys endometrial lining; effective for DUB without structural pathology
• Myomectomy - fibroid removal (25-30% recurrence rate)
• Uterine artery embolization - effective for symptomatic fibroids
• Hysterectomy - definitive treatment when fertility is not desired

Key Points

• Menorrhagia/HMB is one of the most common gynecological complaints.
• Always rule out pregnancy and malignancy.
• In young women presenting at menarche, a bleeding disorder must be excluded.
• The modern preferred term is heavy menstrual bleeding (HMB) per FIGO guidelines.
• A 2025 systematic review (PMID 39617186) provides updated evidence on etiology and diagnosis across adolescent and adult populations.