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Anovulation
Menstrual irregularity and anovulation associated with
excessive ovarian production of male sex hormones, manifested by
hirsutism, oily skin and acne, is the most common endocrine disturbance
of women of reproductive age. As many as 10% of women of reproductive
age suffer from these symptoms, usually referred to as polycystic ovary
syndrome (PCOS) because of the frequent association of the endocrine
disturbance with enlarged ovaries containing multiple follicular cysts.
PCOS is a cause of infertility and it has recently been recognized to be
associated with long-term risks of diabetes and cardiovascular disease.
Despite the fact that PCOS has been known as a
clinical entity for some 60 years, there is still debate about the
criteria that should be used in diagnosing the condition. The causes of
the disorder are more obscure. While there is evidence to suggest that
PCOS has a genetic component, the nature and number of genetic loci
involved, and their mode of inheritance and penetrance are debated.
Arguments supporting claims for primary defects in
hypothalamic/pituitary function, the ovary and adrenal glands, and
insulin and insulin-like growth factor action co-exist in the
literature, making PCOS a disease of theories (25). It appears likely
that PCOS is caused or influenced by more than one gene and may, in
fact, reflect a general metabolic disturbance.
Although polycystic ovaries, which commonly occur in
association with hyperandrogenemic anovulation, can be produced by
various treatments in laboratory animals, it is not evident that these
animal systems bear any pathophysiologic resemblance to the human
syndrome.
While there are several successful therapies for the
anovulatory infertility of PCOS, not all patients respond to standard
treatment and successful ovulation and conception in women with PCOS
more frequently ends inexplicably in early pregnancy loss. It is not
known whether this reflects abnormalities in the germ cells or an
abnormal response of the ovary and/or uterus to ovulation
induction.
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