Can chronic amenorrhea (absence of menstruation) associated with functional hypothalamic amenorrhea (FHA) cause the formation of polycystic ovaries (multiple cysts on the ovaries) in the absence of polycystic ovary syndrome (PCOS) symptoms?

Polycystic Ovarian Morphology in Functional Hypothalamic Amenorrhea

Yes, chronic amenorrhea from functional hypothalamic amenorrhea can absolutely cause polycystic ovarian morphology on ultrasound, even in the complete absence of PCOS symptoms, and this woman's presentation is entirely consistent with FHA-PCOM rather than true PCOS. 1

Understanding the Mechanism

The polycystic appearance on ultrasound in FHA is not due to "eggs building up and becoming cystic" as you hypothesized, but rather reflects a more complex pathophysiological process:

What Actually Happens in FHA-PCOM

• Polycystic ovarian morphology occurs in 41.9-48% of women with FHA, which is substantially higher than the 14-33% prevalence in the general population 1

• The mechanism involves altered intra-ovarian regulation of folliculogenesis that is independent from gonadotropin levels (which are characteristically low in FHA) 1

• These are arrested follicles that accumulate due to the hypothalamic suppression preventing normal follicular development and ovulation, not simply "cystic eggs" 1

Why This Woman's Case Makes Sense

Her clinical picture strongly supports FHA-PCOM rather than misdiagnosed PCOS:

• Lean body type with history of calorie restriction and dieting 1, 2
• No hyperandrogenic features (no hirsutism, no hair loss) 1
• No insulin resistance on laboratory testing 1
• Timing coincides with coming off oral contraceptives after 15 years plus energy deficit from dieting 1, 2

The Heterogeneous Nature of FHA-PCOM

FHA-PCOM represents a heterogeneous subgroup consisting of:

• Approximately 38% with incidental PCOM (normal variant that happens to coexist) 1
• Approximately 10% with some underlying PCOS features that are currently masked by hypothalamic suppression 1
• The remaining cases where PCOM develops as a consequence of the hypothalamic state itself 1

Evidence That PCOM Features May Be Reversible

Critical longitudinal data shows that PCOM in FHA can be reversible:

• In women with FHA who had elevated AMH and PCOS-like features, these features decreased after recovery of menstrual function 3
• After one year of recovered menstrual function, AMH levels, testosterone, and ovarian size all decreased in the majority of women 3
• Only 1 out of 12 women (8%) with initially elevated AMH developed clinical PCOS after recovery, suggesting most PCOM in FHA is a consequence of the hypothalamic state rather than underlying PCOS 3

Why PCOM Is More Common in FHA

Several hypotheses explain the overrepresentation of PCOM in FHA:

• Stress sensitivity: Women with stress-induced FHA show higher PCOM prevalence (57.9%) compared to exercise-induced FHA (31.6%) 1

• Unknown alterations in intra-ovarian folliculogenesis that occur independently of the low gonadotropin environment 1

• Not a simple "buildup" mechanism: The polycystic appearance reflects complex disruption of normal follicular dynamics rather than passive accumulation 1

Distinguishing FHA-PCOM from True PCOS

Key differentiating features in this woman's case:

Clinical Features Favoring FHA-PCOM:

• History of energy deficit (calorie restriction/dieting) 1, 2
• Low or normal BMI (lean body type) 1
• Absence of hyperandrogenic symptoms (no hirsutism, no hair loss) 1
• Timing with stressor (coming off pill + dieting) 1

Laboratory Features Expected in FHA-PCOM:

• Low estradiol levels with negative progestin challenge test 1
• Low or low-normal LH and FSH (not the elevated LH:FSH ratio seen in PCOS) 1, 2
• Normal or only mildly elevated androgens (not the frank hyperandrogenism of PCOS) 1
• Higher SHBG compared to PCOS patients 1

Clinical Implications

This distinction matters for management:

• FHA-PCOM requires correction of energy deficit as primary treatment, not PCOS-directed therapy 1
• Risk of bone density loss from hypoestrogenism needs addressing 1
• If fertility treatment needed, pulsatile GnRH therapy is more appropriate than typical PCOS ovulation induction 1
• The PCOM may resolve with restoration of normal hypothalamic function and menstrual cycles 3

Common Pitfall to Avoid

The major diagnostic error is applying Rotterdam criteria mechanistically (amenorrhea + PCOM = PCOS diagnosis) without considering the clinical context of energy deficit, stress, and absence of hyperandrogenic features 1. This woman was likely misdiagnosed precisely because of this pitfall.