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Click here to view next page of this article Premature Ovarian FailurePremature ovarian failure (premature ovarian failure) is defined as cessation of menses before age 40. Premature ovarian failure presents with amenorrhea, low estrogen levels, and elevated gonadotropins. The term "premature" was coined when it was thought that affected patients had no remaining ovarian follicles. However, investigators have found evidence of ovarian function in about 60 percent of patients with premature menopause or premature ovarian failure. Some patients can spontaneously resume cyclic menstruation and even become pregnant. premature ovarian failure is thought to be a heterogeneous disorder. The prevalence of premature menopause or premature ovarian failure in women under age 40 is estimated to be between 0.3 and 1.0 percent. In women with primary amenorrhea, the prevalence of premature ovarian failure ranges between 10 and 28 percent. In those with secondary amenorrhea, the prevalence is between 4 and 18 percent. The causes of premature menopause or premature ovarian failure can be divided into two distinct categories: follicle depletion and follicular dysfunction. In patients with follicle depletion, either an initial deficiency in primordial follicles. Other chromosomal abnormalities associated with premature ovarian failure include mosaicism and structural abnormalities of the sex chromosomes. Follicle depletion can also be caused by autoimmunity or surgery. Between 10 and 18 percent of patients with premature ovarian failure may have an autoimmune etiology. An increased frequency of premature ovarian failure has been noted in women with Addison's disease, myasthenia gravis, rheumatoid arthritis, and autoimmune thyroiditis. Table 19 Classification of Premature Ovarian Failure Ovarian follicle depletion Deficient initial follicle number Pure gonadal dysgenesis Thymic aplasia/hypoplasia Idiopathic Accelerated follicular atresia X-chromosome related Turner's syndrome X mosaics X deletions Galactosemia Viral agents (e.g., mumps) Autoimmunity latrogenic Oocyte-specific cell-cycle regulation defect Idiopathic Ovarian follicular dysfunction Enzyme deficiencies 17-alpha hydroxylase 17-20 desmolase Cholesterol desmolase Galactose- I -phosphate uridyltransferase Autoimmunity Lymphocytic oophoritis Gonadotropin-receptor-blocking antibodies Antibodies to gonadotropins Signal defects Abnormal gonadotropins Abnormal gonadotropin receptor Abnormal G protein Iatrogenic Idiopathic (resistant ovary syndrome) In follicular dysfunction, the oocytes/follicles fail to function despite adequate gonadotropin levels. Most causes of dysfunction are unclear, but may be related to enzyme deficiencies or signal defects. Women with premature ovarian failure may present with primary or secondary amenorrhea. Many women with primary Differential Diagnosis of Premature Ovarian Failure Prodromal premature ovarian failure Pure gonadal dysgenesis Abnormal karyotype Autoimmune ovarian failure latrogenic ovarian failure Associated with other syndromes: Autoimmune polyglandular syndrome Nonorgan-specific autoimmunity Isolated immunoglobulin A deficiency Idiopathic Miscellaneous causes (rare) Perrault's syndrome Pseudohypoparathyroidism Enzyme deficiencies
Thymic disorders
Pseudo-ovarian failure Thymic disorders Gonadotropin-producing pituitary adenoma Isolated gonadotropin deficiency Hypothyroidism Gonadotropin antibodies TREATMENT Therapy for premature ovarian failure depends primarily on the patient's desire for future pregnancy. Up to 20 percent of patients with premature ovarian failure ovulate spontaneously when the few remaining follicles respond to high circulating levels. Most reported pregnancies in patients with premature ovarian failure occur while patients are receiving hormone replacement therapy, but this does not imply a cause-and-effect relationship. It is not possible to predict the likelihood of ovulation. Pregnancy rates using donor oocytes have been reported to be between 16.8 and 30.0 percent. Treatment of women under age 40 who do not desire pregnancy is fairly straightforward. The long-term risks associated with estrogen deficiency, osteoporosis, and premature cardiovascular disease can be prevented. A dosage of as much as 1.25 mg of conjugated estrogen (Premarin) may be necessary to provide symptom relief in this younger patient population. Patients should be counseled regarding possible spontaneous return of ovarian function and ovulation.
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