Amenorrhea

Basics

Transient, intermittent or permanent absence of menses
Primary amenorrhea:
- Absence of menses at age 15 with normal growth and secondary sexual characteristics or at age 13 with complete absence of secondary sexual characteristics (ie, breast development)
Secondary amenorrhea:
- Absence of menses for more than 3 mo in a patient with prior regular menstrual cycles or 6 mo in patients with irregular menses
- More common than primary amenorrhea
- Pregnancy is the most common cause

Low estrogen:
- Atrophic vaginal mucosa
- Mood swings, irritability
High androgen:
- Truncal obesity
- Hirsutism
- Acne
- Male-pattern baldness
Thyroid exam:
- Tachycardia, goiter, hyperhidrosis–hyperthyroidism
- Bradycardia–hypothyroidism
Pelvic/genital exam
- Underdeveloped or ambiguous genitalia
Tanner staging

Pregnancy test

If pregnancy test is negative, no further testing is needed emergently
Thyroid-stimulating hormone level if concern for thyroid disorder
Basic metabolic panel, Magnesium, Phosphorus if concern for anorexia nervosa
May send luteinizing hormone, follicle stimulating hormone, and prolactin for follow-up by gynecology or primary care physician

Pelvic ultrasound as indicated for ectopic pregnancy workup
Magnetic resonance imaging of the brain with and without contrast if concern for intracranial mass

None needed emergently

Pregnancy
Mullerian agenesis:
- Congenital malformation of the genital tract
- Normal breast development without menarche
- Associated with:
  - Fused vertebrae
  - Urinary tract defects
Transverse vaginal septum
Imperforate hymen
Complete androgen insensitivity syndrome
Asherman syndrome:
- Intrauterine synechiae
- Due to gynecologic instrumentation
Primary ovarian insufficiency
Hypothalamic/Pituitary
Prior CNS infection, trauma, or autoimmune destruction of pituitary
Anorexia nervosa
Depression
Prolactinoma or suprasellar mass
Polycystic ovary syndrome
Medication adverse effect
Contraceptive use
Thyroid disease:
- Hyperthyroid more likely than hypothyroid
Adrenal disease

If amenorrhea is the result of pregnancy, stabilize patient as appropriate for pregnancy

Defer for gynecology evaluation

Admit if ectopic pregnancy cannot be ruled out

Discharge with appropriate referral

Referral to gynecology

Gynecology follow-up is recommended

Pregnancy is the most relevant etiology of amenorrhea in the emergency department:
- Urine pregnancy test (UPT) may give false negative with low urine specific gravity
- UPT sensitivity for β-hCG level may vary depending on type/manufacturer
- High concern for amenorrhea due to pregnancy, specifically an ectopic, may warrant a qualitative serum pregnancy test
Anorexia nervosa is an important consideration in patients with amenorrhea, particularly in adolescents
Hyperprolactinemia from use of antipsychotic drugs is a common etiology of amenorrhea in psychiatric patients
Consider suprasellar mass or prolactinoma in patients with headache or bitemporal hemanopsia

Heiman DL. Amenorrhea. Prim Care. 2009;36:1–17. [PMID:19231599]
Klein DA, Poth MA. Amenorrhea: an approach to diagnosis and management. Am Fam Physician. 2013;87:781–788. [PMID:23939500]
Nawaz G, Rogol AD, Jenkins SM. Amenorrhea. [Updated 2024 Feb 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. https://www.ncbi.nlm.nih.gov/books/NBK482168/
Patrice Committee of the American Society for Reproductive Medicine. Current evaluation of amenorrhea. Fertil Steril. 2006;86:S148–S155. [PMID:17055812]
Rosenberg HK. Sonography of the pelvis in patients with primary amenorrhea. Endocrinol Metab Clin N Am. 2009;38:739–760.
Santoro N. Update in hyper- and hypogonadotropic amenorrhea. J Clin Endocrinol Metab. 2011;96:3281–3288. [PMID:22058375]

Michael H. Morgan

Harshit Singh

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