What endocrine disorders cause uterine bleeding?

From the Guidelines

Endocrine disorders that cause uterine bleeding include polycystic ovary syndrome (PCOS), thyroid dysfunction, hyperprolactinemia, and adrenal disorders, with PCOS being the most common, characterized by irregular ovulation leading to estrogen excess without progesterone opposition, resulting in endometrial overgrowth and irregular bleeding 1.

Causes of Uterine Bleeding

• PCOS: irregular ovulation, estrogen excess, and endometrial overgrowth
• Thyroid dysfunction: hypothyroidism causes heavy menstrual bleeding, while hyperthyroidism leads to lighter, infrequent periods
• Hyperprolactinemia: suppresses gonadotropin-releasing hormone, causing anovulation and irregular bleeding
• Adrenal disorders: Cushing's syndrome or congenital adrenal hyperplasia disrupt hormonal balance through excess cortisol or androgens

Diagnosis and Treatment

• Diagnosis involves hormone level testing, including thyroid function tests, prolactin levels, and androgen panels, along with pelvic ultrasound when indicated 1
• Treatment depends on the specific disorder:

• PCOS: combined hormonal contraceptives or cyclic progestins
• Thyroid disorders: appropriate thyroid hormone replacement or suppression
• Hyperprolactinemia: dopamine agonists like bromocriptine or cabergoline
• Adrenal disorders: specific treatments targeting the underlying cause

Key Considerations

• The American College of Obstetricians and Gynecologists (ACOG) treatment recommendations are based on the assumption that a physician has confirmed the diagnosis and ruled out endometrial and structural pathologies 1
• Medical treatments for abnormal uterine bleeding associated with ovulatory dysfunction include progestin-only contraception and combined hormonal contraception 1

From the FDA Drug Label

In cases of breakthrough bleeding, as in all cases of irregular bleeding per vaginum, nonfunctional causes should be borne in mind and adequate diagnostic measures undertaken. The FDA drug label does not answer the question.

From the Research

Endocrine Disorders Causing Uterine Bleeding

• Endocrine disorders such as hypothyroidism, hyperprolactinemia, and polycystic ovary syndrome (PCOS) are possible causes of abnormal uterine bleeding (AUB) 2
• Chronic anovulation, which can be caused by endocrine disorders, can lead to irregular bleeding, prolonged unopposed estrogen stimulation of the endometrium, and increased risk of endometrial cancer 3
• Anovulatory cycles, owing to immature hypothalamic-pituitary-ovarian axis, is the leading etiology of heavy menstrual bleeding (HMB) and there is an accompanying bleeding disorder in almost 20% of patients with HMB 2
• Thyroid dysfunction is also a possible cause of ovulatory abnormal uterine bleeding, or menorrhagia 3

Specific Endocrine Disorders

• Polycystic ovary syndrome (PCOS) is an endocrine disorder that can cause irregular uterine bleeding associated with anovulation 4
• Hyperprolactinemia is an endocrine disorder that can cause abnormal uterine bleeding (AUB) 2, 3
• Hypothyroidism is an endocrine disorder that can cause abnormal uterine bleeding (AUB) 2, 3

Treatment of Endocrine Disorders Causing Uterine Bleeding

• Treatment of estrogen withdrawal bleeding depends on when in the menstrual cycle bleeding occurs, and anovulatory bleeding is best treated with progestin 5
• Combination oral contraceptives or progestins may regulate menstrual cycles in women with endocrine disorders causing uterine bleeding 3
• Progestogens, and oestrogens and progestogens in combination, are widely used in the management of irregular menstrual bleeding associated with anovulation, but the regime, dose and type of progestogen used vary widely, with little consensus about the optimum treatment approach 4