What is the role of combined oral contraceptives (COCs) in managing abnormal uterine bleeding (AUB) due to adenomyosis?

Combined Oral Contraceptives for Abnormal Uterine Bleeding in Adenomyosis

Combined oral contraceptives are effective for managing abnormal uterine bleeding due to adenomyosis, but they are inferior to the levonorgestrel-releasing intrauterine device (LNG-IUD), which should be offered as first-line therapy. 1

Evidence-Based Treatment Hierarchy

First-Line: LNG-IUD Over COCs

• A recent randomized controlled trial demonstrated that the LNG-IUD provides significantly superior improvement in both pain and bleeding compared to combined oral contraceptives in women with adenomyosis. 1
• The LNG-IUD reduces menstrual blood loss by 71-95% and has efficacy comparable to endometrial ablation, making it the most effective medical option. 1, 2
• LNG-IUD is clinically favored due to its local mechanism of action, lower systemic hormone levels, long duration of action (up to 5 years), and user independence. 1

Second-Line: COCs When LNG-IUD Is Declined or Contraindicated

• Combined oral contraceptives have been shown to reduce painful and heavy menstrual bleeding in randomized controlled trials for adenomyosis. 1
• COCs work by inhibiting the hypothalamic-pituitary-ovarian axis, preventing ovulation, and inducing endometrial atrophy. 3
• For acute heavy bleeding episodes, low-dose COCs administered for 10-20 days provide rapid control. 2

Critical Pre-Treatment Requirements

Before prescribing COCs for adenomyosis-related AUB, you must exclude:

• Pregnancy (beta-hCG test mandatory) 2
• Cardiovascular contraindications: COCs are absolutely contraindicated in hypertensive women due to 6-9 fold increased risk of myocardial infarction and 8-15 fold increased risk of stroke. 4
• Thromboembolic risk factors: History of venous thromboembolism is an absolute contraindication. 4, 5
• Structural pathology requiring surgical intervention (fibroids, polyps) through imaging. 2
• Endometrial hyperplasia or malignancy (endometrial biopsy if indicated by risk factors). 2

Important Limitations of COCs in Adenomyosis

• COCs will not treat bulk symptoms associated with adenomyosis (uterine enlargement, pressure symptoms). 1
• The presence of concomitant adenomyosis does not decrease the effectiveness of hormonal treatments for heavy menstrual bleeding, but LNG-IUD remains superior. 1
• If bleeding persists after 3-6 months of COC therapy, further investigation with imaging or hysteroscopy is mandatory to rule out treatment failure or alternative diagnoses. 2, 4

Practical COC Prescribing Strategy

• Start with standard-dose COCs (30-35 mcg ethinyl estradiol) in continuous or extended regimens to minimize withdrawal bleeding and maximize endometrial suppression. 6
• If breakthrough bleeding occurs, consider increasing estrogen content from 20 mcg to 35 mcg daily or decreasing the hormone-free interval from 7 days to 4-5 days. 6
• Add NSAIDs (5-7 days) for breakthrough bleeding while on COCs, as they reduce menstrual bleeding by 30-50% and can be safely combined with hormonal methods. 2

When to Abandon COCs and Escalate Care

• If COCs fail to control bleeding after 3-6 months, strongly reconsider LNG-IUD placement or refer for interventional options (uterine artery embolization, which shows 94% short-term symptom improvement in adenomyosis). 1, 4
• Hysterectomy should be reserved as last resort after conservative measures fail, given increased long-term risks of cardiovascular disease, osteoporosis, and dementia. 1

Common Pitfall to Avoid

Do not prescribe COCs to women with hypertension, cardiovascular disease, or thrombotic risk factors — these patients require progestin-only methods (LNG-IUD or oral progestins) instead. 4 The cardiovascular risks of COCs in these populations far outweigh any bleeding control benefits.