Induce ovulation only if BMI ≥18.5 kg/m2 and after energy balance normalization
STEP 1 — Gather Information
Collect patient’s height and weight to calculate BMI, review recent weight trends, assess caloric intake and exercise levels, confirm FHA diagnosis after excluding organic causes, and obtain menstrual and obstetric history.
STEP 2 — Rule In / Rule Out
Is the calculated BMI ≥18.5 kg/m²? If yes, proceed to evaluate energy balance; if no, rule out ovulation induction and advise weight gain.
STEP 3 — Classify or Stratify
Assess whether energy balance is normalized: stable weight for ≥3 months, improved nutrition, reduced excessive exercise, and resolution of psychosocial stressors. Classify as energy deficit corrected or not corrected.
STEP 4 — Decide
If BMI ≥18.5 kg/m² and energy deficit corrected, proceed with ovulation induction (e.g., pulsatile GnRH or gonadotropins); otherwise, continue lifestyle interventions and reassess in 1–2 months.
Clinical Guardrails / Mimics / Pitfalls
Do not induce ovulation in women with BMI <18.5 kg/m² due to increased risk of fetal loss, preterm labor, and cesarean delivery; avoid overlooking persistent energy deficit or psychological stressors; ensure FHA is not mistaken for PCOS or ovarian insufficiency; do not use ovulation drugs as a substitute for nutritional and behavioral therapy.
Concrete Clinical Example
A 26‑year‑old runner presents with 9‑month amenorrhea, BMI 18.2 kg/m², recent 5‑kg weight loss, and high exercise volume. BMI below threshold and energy deficit not corrected; ovulation induction is held, and she is referred for dietary counseling and exercise modification to achieve BMI ≥18.5.
Source: Functional Hypothalamic Amenorrhea: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2017, DOI:10.1210/jc.2017-00131
TODO: consider adding scripts/calc.py for the endo-fha-ovulation-induction-bmi-threshold calculator