In part 1, we will discuss the pathophysiology of PCOS, its diagnostic criteria, and insulin and leptin resistance. FSH acts on the ovary to help grow and mature small follicles. Growth of the dominant follicle generates estradiol production and elevated estrogen levels signal FSH production to cease via a negative feedback system, but a high and sustained estrogen level will trigger a one-time surge of LH which causes ovulation to occur.
This increase in LH increases theca cell stimulation see Fig 1 , which produces androstenedione and testosterone, two androgens, and the resulting hyperandrogenic milieu of the ovary precludes normal follicular growth, maturation and ovulation. The ovary, then, becomes comprised of many small, antral follicles that never become dominant. The collection of these follicles can cause an increase in the size of the ovaries and generate a slightly elevated basal serum estrogen level.
It remains unknown why PCOS occurs and whom it affects, but it is thought that genetics and environmental factors have a complex interplay in its emergence and clinical manifestations. PCOS is not defined or diagnosed by one simple symptom and is often a diagnosis of exclusion for women who have oligo-ovulation and evidence of hyperandrogenism such as acne alopecia and hirsutism male-pattern hair growth and texture once other disorders are excluded.
It affects women of all shapes, sizes, and backgrounds. Although symptoms can start at menarche, most clinicians are reluctant to diagnose a relatively newly menstruating adolescent with PCOS as menstrual cycle irregularity is normal in the first year post menarche and can resolve in time. Hyperandrogenism is diagnosed either clinically by the clinician observing androgenic symptoms or biochemically such as elevated serum free testosterone levels. These criteria were revised in by an international committee which made a few changes.
The guidelines also state that if a woman has irregular menstrual cycles and hyperandrogenism that the ultrasound is not necessary for diagnosis, although many clinicians still prefer to perform this. In PCOS-affected women, an elevated AMH level is reflective of a higher number of follicles arrested in the pre-antral and antral stages that fail to ovulate. Other conditions that can cause irregular menstrual cycles pregnancy, hypo- and hyperthyroidism, ovarian failure and hyperprolactinemia and hyperandrogenism congenital adrenal hyperplasia, adrenal tumor and androgen-secreting tumor must be ruled out first, so in addition to serum bHCG levels, basal FSH and LH levels, thyroid stimulating hormone TSH , prolactin, total and free testosterone, 17 hydroxyprogesterone 17OHP , dehydroepiandrosterone sulfate DHEAS are drawn.
One of the most difficult differential diagnoses is discerning a woman with functional hypothalamic amenorrhea FHA versus a lean woman with PCOS. Both conditions are characterized by anovulation and ovaries which appear to have many small follicles in a resting state.
While hyperandrogenism is not a component of FHA, women with the condition may have hirsutism due to their ethnicity, further confusing the clinical picture.
In addition to the health consequences of IR such as metabolic syndrome and type 2 diabetes mellitus , it also exacerbates and contributes to hyperandrogenism in a patient population who is already suffering from it. The gold standard for diagnosing insulin resistance is to use a hyperinsulinemic euglycemic clamp, a test which must be performed in a hospital setting.
To most, this is unreasonable, so indirect testing for IR is done. In women with PCOS in a preconception clinical setting, the suggestion is to do perform an oral glucose tolerance test OGTT given the high risk of women with PCOS to develop impaired glucose tolerance and gestational diabetes in pregnancy. Hypersecretion of luteinizing hormone LH is a significant cause of infertility and miscarriage in women with the polycystic ovary syndrome. Many theories have been suggested for the aetiology of pituitary oversecretion of LH.
These include increased pulsatility of gonadotrophin releasing hormone GnRH hypothalamic dysfunction, altered pituitary sensitivity to GnRH, hyperinsulinaemic stimulation of the pituitary gland and perturbed ovarian—pituitary feedback of steroid hormones. None of these hypotheses fully explain the phenomenon of LH hypersecretion and there has been much debate in the literature on this subject.
This paper reviews some of the important clinical studies that have examined the evolving story of hypersecretion of LH and presents in-vivo and in-vitro evidence that suggests that disordered ovarian—pituitary feedback is central to the problem, possibly through a perturbed secretion of nonsteroidal ovarian hormones. Most users should sign in with their email address. If you originally registered with a username please use that to sign in.
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Prolactin is a pituitary hormone that stimulates and sustains milk production in nursing mothers. However, it is important to check for high prolactin levels in order to rule out other problems, such as a pituitary tumor, that might be causing PCOS-related symptoms. ANDRO is a hormone that is produced by the ovaries and adrenal glands. Sometimes high levels of this hormone can affect estrogen and testosterone levels. Progesterone is produced by the corpus luteum after ovulation occurs.
Progesterone helps to prepare the uterine lining for pregnancy. For women with PCOS, especially those who are trying to become pregnant using fertility medications, Progesterone levels are checked about 7 days after it is thought that ovulation occurred. If the progesterone level is low the egg was probably not released. This test is especially important because sometimes women with PCOS can have some signs that ovulation is occurring however, when the progesterone test is done, it shows that ovulation did not occur.
If this happens, your body is may be producing a follicle and preparing you to ovulate, but for some reason the egg is not actually being released from the ovary. This information helps your physician possibly adjust fertility medication for the next cycle to encourage the release of the egg. Estrogen is the female hormone that is secreted mainly by the ovaries and in small quantities by the adrenal glands. The most active estrogen in the body is called estradiol.
A sufficient amount of estrogen is needed to work with progesterone to promote menstruation. This may be due to the fact that the high levels of insulin and testosterone found in women with PCOS are sometimes converted to estrogen. TSH stands for Thyroid Stimulating Hormone and is produced by the thyroid, a gland found in the neck.
TSH is checked to rule out other problems, such as an underactive or overactive thyroid, which often cause irregular or lack of periods and anovulation. Due to the recent research that PCOS is probably caused by insulin resistance, physicians are beginning to check glucose levels as a factor when diagnosing PCOS.
Most women with polycystic ovary syndrome should have an Fasting Plasma Glucose Test and a Glucose Tolerance Test at diagnosis and periodically thereafter, depending on risk factors. A high glucose level can indicate insulin resistance, a diabetes-related condition that contributes to PCOS.
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