Amenorrhoea is an early symptom of anorexia nervosa and in a minority of patients may even precede the onset of weight loss. Amenorrhoea is an almost necessary criterion for the diagnosis of anorexia nervosa. An exception is when a patient takes a contraceptive pill which in fact replaces some of the hormonal deficit and may lead her to say she still has her periods.
Generally, when the patient is undernourished, levels of gonadotrophins and oestrogens in the blood are found to be low or undetectable. (UJ Not only do malnourished patients show low blood levels of luteinizing hormone and follicle-stimulating hormone, but the secretion patterns of these pituitary hormones regress to patterns of earlier development. For example, severely wasted patients display an infantile luteinizing hormone secretory pattern with a lack of major fluctuations over the course of 24 h. With some degree of weight gain a pubertal secretory pattern appears, consisting first of a sleep-dependent increase of luteinizing hormone at night, and later displaying more frequent fluctuations.(78) When a patient is still malnourished the ultrasound pelvic examination will reveal that ovarian volume is much smaller than in normal women.(79) Three stages can be discerned in the appearance of the ovaries as the patient gains weight:
1. small amorphous ovaries;
2. multifollicular ovaries (with cysts 3-9 mm in diameter);
3. dominant follicle (10 mm or more in diameter).
At the same time there is a corresponding return of hormonal secretion; follicle-stimulating hormone appears first, followed by luteinizing hormone and finally oestradiol which leads to enlargement of the uterus. (89
These abnormalities signify that the patient is infertile and remains so until endocrine function recovers. Pregnancy occasionally occurs as the patient is still underweight and improving but before the appearance of the first menstrual period. (81 The pregnancy carries a risk of poor fetal growth during the first trimester, albeit with some 'catch-up' growth during the neonatal period.(82) Occasionally an underweight anorexic patient may seek treatment at an infertility clinic. Treatment with gonadotrophin-releasing hormone may restore fertility, but this practice has been severely criticized. (83)
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