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Recognition of Functional Hypothalamic Anovulation

المؤلف:  Wass, J. A. H., Arlt, W., & Semple, R. K. (Eds.).

المصدر:  Oxford Textbook of Endocrinology and Diabetes

الجزء والصفحة:  3rd edition , p1290-1292

2026-10-29

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The diagnosis of functional hypothalamic anovulation entails excluding all other causes of amenorrhoea and anovulation. Reduced GnRH drive manifests as FSH>LH with low oestradiol (<60 pg/ ml) and progesterone concentrations (<1 ng/ ml). A thorough search for organic causes must be conducted. While focal neurological signs would be certain to raise suspicion of a central organic cause, conditions such as adult- onset hydrocephalus may be accompanied by dizziness or vague symptoms, rather than lateralizing symptoms. In most instances, if suspected, organic causes can be confirmed by magnetic resonance imaging (MRI). Conditions such as coeliac dis ease (gluten enteropathy) and irritable bowel syndrome that result in nutritional insufficiency should be excluded as well.

The epidemiology of FHA is not well described. In addition to individual factors, there appears to be a dose– response relationship between the type and severity of stress and the proportion of individuals who develop amenorrhoea. To what extent more subtle forms of anovulation and luteal insufficiency are due to intermittent or mild reductions in GnRH drive is difficult to ascertain in general clinical practice because the manifestations may be clinically subtle or occult. Oligoasthenospermia may sometimes be the male analogue of functional hypothalamic anovulation. The behavioural causes of FHH may differ in men and women, but this is an area that has received minimal investigative attention. A combined metabolic and psychogenic stressor, a war drill, acutely and reversibly raised cortisol levels while suppressing testosterone and gonadotropin levels in men. Short- term fasting studies suggest that the GnRH pulse generator of men may be more sensitive to metabolic challenge than that of women. Available evidence suggests that extreme forms of hypothalamic hypogonadism, such as anorexia nervosa or bulimia affect 3% of women, that FHA unrelated to an eating disorder affects roughly 5% of college- aged women , that recreational running is associated with a roughly 55% prevalence of cycles that are anovulatory or display luteal insufficiency, and that men are susceptible to functional reductions in GnRH drive without obvious clinical manifestations.