Definition
• Normal menses: Avg age menarche 12.8 yr (Pediatr Rev 1992;13:43)
• 2–2.5 yr after breast budding; 1 yr after growth spurt
• 1° amenorrhea: Any one of the following:
• No menses by age 16 + nml pubertal growth and development
• No menses by age 15 + abn pubertal growth and development
• No menses 2 yr after completed sexual maturation
• 2° amenorrhea: Absence of menses for 6 mo or 3 cycles in pt w/ established menses
Evaluation of 1° Amenorrhea
• 4 groups based on pubertal maturation and internal genitalia
• Breast (−)/uterus (+): Lack of estrogen 2/2 lack of gonads, HPO axis problem, or defect in estrogen production. Check FSH to direct studies
• Breast (−)/uterus (−): Rare; suspect genetic male whose gonads produce MIS (suppresses internal F genital dev) but insuff testosterone to produce M genitals
• Breast (+)/uterus (−): Phenotypically female, but check karyotype for Ddx
• CAIS (testicular feminization): Develop breasts 2/2 unopposed estrogen from gonad + adrenals. No/sparse axillary or pubic hair. Gonadal testes must be removed after pubertal dev is complete 2/2 ↑ rate malignancy
• Müllerian agenesis (Rokitansky–Küster–Hauser syndrome): ↑ risk renal (30%), skeletal (12%), and cardiac problems
• Breast (+)/uterus (+): Eval HPO axis, U/S for obstruction (often cyclic pain)
Evaluation of 2° Amenorrhea
• Multi causes: Stress, anorexia nervosa, systemic dz (IBD, DM, thyroid dz, PCOS)
• History: Caloric intake, wt Δ, diet, meds, headaches, visual change, galactorrhea
• PE: BMI, anorexia stigmata, visual fields, CN, breast exam, androgen excess, pelvic
• Labs: β-hCG, LH, FSH, fT4, TSH, prolactin (
w/ galactorrhea), DHEA-S, and testosterone (if signs/symptoms) of virilization
• Prolactin: Mild ↑ usually 2/2 meds, breast stim, stress, hypothyroid
• Other labs: Adol w/ nml uterus/vagina, FSH, LH if elevated
• If ↑, check karyotype; r/o Turner mosaicism w/ ovarian failure vs. other causes of ovarian failure (autoimmune, galactosemia, etc.)
• If ↓ or nml, think hypothalamus × image; if no tumor, consider stress, AN, etc.
• Progesterone challenge: Give PO medroxyprogesterone acetate 5–10 mg qd × 5–10 d
• + withdrawal bleed: Uterus nml & primed by estrogen, so ovaries intact; PCOS
• − withdrawal bleed: Abn uterus or no estrogen, e.g., Asherman syndrome, AN, and other causes of hypothalamic amenorrhea
• Trial of combined estrogen/progesterone
