Infertility is a common and often distressing problem affecting approximately 1 in 6 couples. Statistics confirm that the incidence of infertility is not actually increasing. More couples are, however, seeking help and advice as treatments become more readily available and effective. Having worked in the specialist area of infertility for fifteen years, I appreciate that many couples find a diagnosis of polycystic ovarian syndrome (PCOS) confusing and difficult to understand. I have therefore chosen to reflect on this particular cause of infertility in order to increase my own knowledge, thus enabling me to readily supply information and advice to women and their partners.

PCOS is a highly variable and individual disorder which was first described by Drs. Stein and Leventhal in 1935. They identified a group of infertile women who had menstrual abnormalities and enlarged ovaries (now known as polycystic ovaries). They also described hirsutism and obesity amongst this group. Not all women with polycystic ovaries however, will exhibit these features. Goldzieher J. W. and Green J. A. (1962) reported that in women with surgically proven polycystic ovaries, 20% had no menstrual irregularities, 50% were not obese and 31% were not hirsute. Polson et. al. (1988) confirmed these findings and reported that polycystic ovaries are found in 22% of the normal population i.e. women who had not sought treatment for menstrual disturbances, infertility or hirsutism.

PCOS may be classified using three main criteria:

1. Clinical presentation, 2. Biochemical characterisation and 3. Characterisation of ovarian abnormalities.

It is these three criteria which are important for the diagnosis and classification of PCOS.

Most women with PCOS have a history of normal menstrual age but develop irregular cycles after the menarche. It is clear therefore that some women presenting with infertility may have had physiological difficulties in their teenage years, and may have foreseen the impact that this would have on their reproductive health in the future. Women with PCOS often have excessive hair growth and may be overweight. Yen (1980) noted that more than 80% of women with PCOS were obese prior to the onset of puberty. Although obesity is frequently associated with this condition it is unclear whether it is an intrinsic component or a predisposing state as weight loss is frequently associated with the correction of hormonal abnormalities and the re-establishment of regular ovulation.

As there is a high prevalence of PCOS in families of affected individuals, the syndrome may have a genetic component (Hauge et. al., 1988). Hypertension, diabetes, insulin resistance and obesity occur more often in families of PCOS women, whilst endocrine abnormalities and disturbed testicular function have been described in male family members. A recent study of familial PCOS has identified premature balding in male relatives as the male phenotye of PCOS (Carey et. al., 1993).

Biochemical assessment of women with PCOS will now be discussed and involves assessing hormonal levels in the blood stream. At the time of birth a woman has between 200,000 and 400,000 primordial follicles within each ovary. As a consequence of a cyclic release of hormones the menstrual cycle occurs, a primordial follicle will mature during each cycle and a mature oocyte will be released. Follicle stimulating hormone (FSH) and Leutenising hormone (LH) are Gonadotrophic hormones released by the anterior pituitary gland which act directly on the ovary. These hormones convert pre-antral follicles to antral or Graafian follicles and each one appears to exert its effects at different locations within the follicle. The granulosa cells of the follicles bind FSH whereas only the cells of the theca interna bind LH. Proliferation of the granulosa and thecal cells cause an increase in follicular size. During this phase of growth the follicle will increase its synthesis of androgens from acetate and cholesterol and this conversion is greatly stimulated by LH As the follicle continues to increase In size the synthesis of oestrogen's increases and the largest more advanced follicle releases steroids into the circulation. These steroids feedback negatively to the pituitary and this leads to a progressive reduction in circulating FSH and therefore limits development of further follicles. Oestrogen, in conjunction with FSH plays a crucial role within the follicle towards the second phase of growth. Together they stimulate the appearance of LH binding sites on the outer layer of the granlosa cells which previously lacked them. The Graafian follicle will die unless a brief surge of high levels of gonadotrophin coincides with the appearance of these LH receptors. The surge of LH has two effects. Firstly, ovulation occurs and the oocyte is expelled from the follicle and secondly, it changes the whole endocrinology of the follicle, forming a corpus luteum after ovulation. The corpus luteum then secretes progesterone and some oestrogens which will support a developing embryo.

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