Chapter 051. Menstrual Disorders and Pelvic Pain (Part 3)

Algorithm for evaluation of amenorrhea. β-hCG, human chorionic gonadotropin; PRL, prolactin; FSH, follicle-stimulating hormone; TSH, thyroidstimulating hormone.Hypogonadotropic Hypogonadism Low estrogen levels in combination with normal or low levels of LH and FSH are seen with anatomic, genetic, or functional abnormalities that interfere with hypothalamic GnRH secretion or normal pituitary responsiveness to GnRH. Although relatively uncommon, tumors and infiltrative diseases should be considered in the differential diagnosis of hypogonadotropic hypogonadism (Chap. 333). These disorders may present with primary or secondary amenorrhea.They may occur in association with other features suggestive of hypothalamic or pituitary dysfunction such as short stature, diabetes insipidus,...
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Chapter 051. Menstrual Disorders and Pelvic Pain (Part 3) Chapter 051. Menstrual Disorders and Pelvic Pain (Part 3) Algorithm for evaluation of amenorrhea. β-hCG, human chorionicgonadotropin; PRL, prolactin; FSH, follicle-stimulating hormone; TSH, thyroid-stimulating hormone. Hypogonadotropic Hypogonadism Low estrogen levels in combination with normal or low levels of LH andFSH are seen with anatomic, genetic, or functional abnormalities that interferewith hypothalamic GnRH secretion or normal pituitary responsiveness to GnRH.Although relatively uncommon, tumors and infiltrative diseases should beconsidered in the differential diagnosis of hypogonadotropic hypogonadism(Chap. 333). These disorders may present with primary or secondary amenorrhea.They may occur in association with other features suggestive of hypothalamic orpituitary dysfunction such as short stature, diabetes insipidus, galactorrhea, orheadache. Hypogonadotropic hypogonadism may also be seen following cranialirradiation. In the postpartum period, it may be due to pituitary necrosis (Sheehansyndrome) or lymphocytic hypophysitis. Because reproductive dysfunction iscommonly associated with hyperprolactinemia, either from neuroanatomic lesionsor medications, prolactin should be measured in all patients withhypogonadotropic hypogonadism (Chap. 333). Isolated hypogonadotropic hypogonadism (IHH) is more common in menthan women and is often associated with anosmia. IHH generally presents withprimary amenorrhea. A number of genetic causes of IHH have been identified(Chaps. 340 and 341). Functional hypothalamic amenorrhea (HA) is caused by a mismatchbetween energy expenditure and energy intake. Leptin secretion may play a keyrole in transducing the signals from the periphery to the hypothalamus in HA. Thehypothalamic-pituitary-adrenal axis may also play a role. The diagnosis of HA cangenerally be made on the basis of a careful history, physical examination, and thedemonstration of low levels of gonadotropins and normal prolactin levels. Eatingdisorders and chronic disease must be specifically excluded (Chap. 76). Anatypical history, headache, signs of other hypothalamic dysfunction, orhyperprolactinemia, even if mild, necessitates cranial imaging with CT or MRI toexclude a neuroanatomic cause. Hypergonadotropic Hypogonadism Ovarian failure is considered premature when it occurs in women youngerthan age 40. Ovarian failure is associated with the loss of negative-feedbackrestraint on the hypothalamus and pituitary, resulting in increased FSH and LHlevels. FSH is a better marker of ovarian failure as its levels are less variable thanLH. As with natural menopause, premature ovarian failure (POF) may wax andwane, and serial measurements may be necessary to establish the diagnosis. Once the diagnosis of POF has been established, further evaluation isindicated because of other health problems that may be associated with POF. Forexample, POF is seen in association with a variety of chromosomal abnormalitiesincluding Turner syndrome, autoimmune polyglandular failure syndromes, radio-and chemotherapy, and galactosemia. In the majority of cases, however, a cause isnot determined. The recognition that early ovarian failure occurs in premutationcarriers of the fragile X syndrome is important because of increased risk of severemental retardation in male children with FMR1 mutations. Hypergonadotropic hypogonadism occurs rarely in other disorders, such asmutations in the FSH or LH receptors. Aromatase deficiency and 17α-hydroxylasedeficiency are associated with elevated gonadotropins with hyperandrogenism andhypertension, respectively. Gonadotropin-secreting tumors in women ofreproductive age generally present with high, rather than low, estrogen levels andcause ovarian hyperstimulation or dysfunctional bleeding. Amenorrhea Caused by Ovulatory Disorders: Treatment Amenorrhea is almost always associated with chronically low levels ofestrogen, whether it is caused by hypogonadotropic hypogonadism or ovarianfailure. Development of secondary sexual characteristics requires gradual titrationof estradiol replacement with eventual addition of a progestin. Symptoms ofhypoestrogenism can be treated with hormone replacement therapy or oralcontraceptive pills. Patients with hypogonadotropic hypogonadism who areinterested in fertility require treatment with pulsatile GnRH or exogenous FSH andLH, whereas patients with ovarian failure can consider oocyte donation, which hasa high chance of success in this population. Polycystic Ovarian Syndrome (PCOS) This is diagnosed based on the presence of clinical or biochemical evidenceof h ...