Approach to a Patient with Hypomenorrhea
The diagnostic approach to hypomenorrhea (scanty menstruation) should focus on identifying underlying causes such as functional hypothalamic amenorrhea (FHA), polycystic ovarian morphology (PCOM), or other endocrine disorders through a systematic evaluation of hormonal status, anatomical features, and lifestyle factors. 1
Initial Assessment
History Taking
- Assess menstrual patterns including onset, frequency, duration, and amount of flow 1
- Evaluate for stress, excessive exercise, weight loss, and psychological disorders as these are common factors in FHA 1
- Inquire about eating habits and caloric intake as energy deficit is a relevant and frequent cause of FHA 1
- Document medication use, especially hormonal contraceptives that may affect menstrual flow 1
Physical Examination
- Measure BMI and assess for signs of weight loss or malnutrition 1
- Evaluate for signs of hyperandrogenism (acne, hirsutism) which may suggest PCOS 1
- Check for galactorrhea which may indicate hyperprolactinemia 2
- Assess Tanner staging in adolescents to evaluate pubertal development 1
Laboratory Investigations
First-Line Testing
- Pregnancy test to exclude pregnancy as a cause 1
- Serum FSH, LH, estradiol to assess ovarian function 1
- Prolactin levels to rule out hyperprolactinemia 1
- TSH to exclude thyroid dysfunction 1
Additional Testing Based on Initial Results
- If LH:FSH ratio >2, consider PCOS 1
- If LH:FSH ratio <1 (found in about 82% of FHA patients), consider FHA 1
- Consider AMH levels as they correlate with antral follicle count and can help assess ovarian reserve 1
- Androgens (testosterone, DHEA-S) if signs of hyperandrogenism are present 1
Imaging Studies
- Pelvic ultrasound to assess:
- Consider brain MRI if hyperprolactinemia is confirmed to rule out pituitary adenoma 2
Diagnostic Challenges
- Differentiating between FHA with PCOM (FHA-PCOM) and PCOS can be challenging 1
- Key differentiating factors include:
- Presence of typical causes for FHA (stress, energy deficit, excessive exercise) 1
- Low endometrial thickness suggesting estrogen deficiency in FHA 1
- Low LH levels in FHA versus elevated LH in PCOS 1
- Progestin challenge test may help (although up to 60% of FHA patients may still have withdrawal bleeding) 1
Management Approach
For FHA-Related Hypomenorrhea
- Address underlying causes:
- Hormone replacement therapy to prevent bone loss and other consequences of hypoestrogenism 1
- Consider oral contraceptives if contraception is needed 1
For PCOS-Related Hypomenorrhea
- Lifestyle modifications to address metabolic risks 1
- Cyclic progestogen to induce regular withdrawal bleeding and prevent endometrial hyperplasia 3
- Combined oral contraceptives, especially for patients with hyperandrogenism 3
For Hyperprolactinemia-Related Hypomenorrhea
- Bromocriptine or other dopamine agonists to normalize prolactin levels 2
- Monitor for side effects such as nausea, dizziness, and potential behavioral changes 2
Follow-Up and Monitoring
- Bone mineral density testing for patients with prolonged hypoestrogenic states 1
- Regular monitoring of menstrual patterns to assess treatment response 1
- In patients with FHA, monitor for resumption of normal menstrual cycles before considering fertility treatments 1
- For patients using hormonal treatments, assess satisfaction and side effects at follow-up visits 1
Special Considerations
- Patients with FHA-PCOM represent a special subpopulation that requires careful evaluation 1
- Almost half of women with FHA have PCOM, making this an important clinical entity to recognize 1
- For patients desiring pregnancy, address underlying causes of FHA and ensure BMI ≥18.5 kg/m² before ovulation induction 1
- Consider complementary approaches for associated dysmenorrhea such as heat therapy, acupressure at LI4 or SP6 points, and NSAIDs 1, 4