Amenorrhea: Understanding Causes, Types, Evaluation, and Management

Evaluation of Amenorrhea

Amenorrhea refers to the absence of menstruation and can be classified into primary and secondary types.

Types of Amenorrhea

• Primary Amenorrhea: Absence of menstruation by age 15 if secondary sexual characteristics (such as pubic hair and breast development) have started. However, we need to start worrying by age 13 if these characteristics are absent by that time.
• Secondary Amenorrhea: Cessation of menstruation for three cycles in women with regular cycles or six months in a woman with irregular cycles.

Etiological Classification of Amenorrhea

Causes Arising from the Brain (Hypothalamic Pituitary Disorders)

• Functional Hypothalamic Amenorrhea: Caused by stress, weight loss, or excessive exercise.
• Hyperprolactinemia: Can result from prolactinoma or certain medications.
• Sheehan Syndrome: Post-delivery condition due to excessive blood loss.
• Brain Tumors: Such as craniopharyngioma or germinoma.
• Kallman Syndrome: A genetic condition affecting puberty onset.

Ovarian Causes

• Polycystic Ovary Syndrome (PCOS): A common cause of secondary amenorrhea.
• Congenital Adrenal Hyperplasia (CAH): Late onset form.
• Primary Ovarian Insufficiency: Includes autoimmune, iatrogenic, and idiopathic causes.
• Turner Syndrome: A genetic condition.
• Androgen Insensitivity Syndrome: A genetic condition affecting male hormone sensitivity.

Uterine and Outflow Tract Abnormalities

• Müllerian Agenesis (MRKH Syndrome): A congenital abnormality.
• Transverse Vaginal Septum: Abnormality in the vaginal canal.
• Imperforate Hymen: A condition where the hymen covers the vaginal opening.
• Asherman Syndrome: Uterine cavity obliteration due to infections or surgical procedures.

Endocrine and Systemic Disorders

• Thyroid Dysfunction: Hypothyroidism or hyperthyroidism.
• Cushing’s Syndrome: A disorder caused by excess cortisol.
• Chronic Systemic Illness: Conditions such as diabetes or autoimmune diseases.

Evaluation Approach

History and Physical Examination

• Age of menarche, growth patterns, and family history.
• Presence of secondary sexual characteristics like breast development and pubic hair.
• Symptoms of systemic diseases like weight changes, headaches, and galactorrhea (milk secretion).

Laboratory Tests

• hCG (to rule out pregnancy).
• FSH, LH, and estradiol (to differentiate ovarian from central causes).
• Prolactin (elevated in hyperprolactinemia).
• TSH and Free T4 (for thyroid dysfunction).
• Androgen levels (Testosterone, DHEA-S for PCOS and adrenal disorders).
• Karyotyping (for Turner syndrome, androgen insensitivity syndrome).

Imaging Studies

• Pelvic Ultrasound (to assess the uterus and ovaries).
• MRI Brain (if hypothalamic or pituitary pathology is suspected).
• Hysteroscopy/Sonohysterography (for Asherman syndrome evaluation).

Management of Amenorrhea

• Functional Hypothalamic Amenorrhea: Lifestyle modifications, nutritional therapy, and stress reduction.
• Hyperprolactinemia: Dopamine agonists such as bromocriptine and cabergoline.
• PCOS: Weight loss, oral contraceptive pills (OCPs), and metformin.
• Primary Ovarian Insufficiency: Hormone replacement therapy (HRT).
• Anatomic Abnormalities: Surgical correction if necessary.
• Endocrine Disorders: Treatment based on underlying causes (e.g., thyroid replacement or adrenal suppression).