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number of fully-formed cells is around 300,000 – and when your body’s reproductive system is activated by puberty’s cascade of sex hormones, pumped into your bloodstream by the ovaries and adrenal glands, then each month about 20 of these egg cells, each encased in a sac called a follicle, begin to mature. One follicle eventually becomes dominant while the others shrink away. The egg within the dominant follicle continues ripening to maturity, then exits the ovary and enters the adjacent fallopian tube either to be fertilized or, if conception doesn’t happen, expelled from the body during menstruation.

      But this normal cycle relies on a complex web of hormones being present at the right time, in the right amounts, for ovulation to happen. Having PCOS often interferes with this, affecting your ovaries’ abilities to nurture, mature and release an egg each month.

      The best way to get to grips with how your ovaries are affected by PCOS is to compare a ‘normal’ menstrual cycle with a typical PCOS cycle.

      THE NORMAL MENSTRUAL CYCLE

      The length of the menstrual cycle can vary from a short 21 days to a long cycle of 40 days. The length of the cycle is calculated by counting the first day of bleeding as Day 1 and then counting until the very last day before the next bleed (period). The average menstrual cycle is commonly described as 28 days, although this may be true for only one in 10 women.

      In a normal menstrual cycle lasting approximately 28 days, the first half (called the follicular phase) starts on the first day of your period and lasts for about 14 days. In this phase the pituitary gland releases low levels of FSH (follicle-stimulating hormone) to stimulate the follicles in the ovary to ripen their eggs and produce the hormone oestrogen, which causes the lining of the womb to start to thicken in preparation for pregnancy. When levels of oestrogen are high enough, the pituitary gland produces a large amount of LH (luteinizing hormone) and the dominant matured follicle in the ovary releases its egg into the fallopian tubes towards the womb.

      After ovulation comes the second stage of the menstrual cycle, called the luteal phase. Here the cells from the burst follicle collapse to form a ‘cyst’, or new kind of follicle, called the corpus luteum. The corpus luteum now produces progesterone as the main hormone of the second half of the cycle. Progesterone causes the thickened lining of the womb to secrete nutrients ready to receive the fertilized egg. If the egg is fertilized by a sperm following intercourse it will implant itself in the womb lining, and the corpus luteum will continue to grow to protect the pregnancy. If it isn’t fertilized 14 days after ovulation, the corpus luteum stops producing progesterone and oestrogen. The thickened womb lining breaks down and is shed as a period, ready for the whole cycle to start again.

      WHAT HAPPENS DURING A PCOS CYCLE?

      The diagram opposite shows a normal menstrual cycle compared to a PCOS cycle. With PCOS, LH levels are often high when the menstrual cycle starts. The levels of LH are also higher than FSH levels. Because the LH levels are already quite high, the surge that sets off the chain-reaction causing ovulation doesn’t happen. Without this LH surge, ovulation doesn’t occur and periods are irregular.

      WHAT DOES A POLYCYSTIC OVARY LOOK LIKE?

      Polycystic means ‘many cysts’ and gives the condition its name, but in actual fact in PCOS, the word ‘cyst’ simply means an empty egg follicle. A polycystic ovary usually has 8 to 12 or more cysts on its surface. Each cyst measures 2–9 mm in size (see diagram opposite).

      A cyst is a fluid-filled sac, and in PCOS that means the empty follicles that are in ‘suspended animation’ – not given the right hormones in the right amounts at the right time. If you’ve got polycystic ovaries the follicles may stop growing too early, preventing the release of an egg. Instead of bursting to release the egg, they gradually build up on the ovaries to form lots of small cysts which are actually swollen egg chambers waiting for the right hormone to trigger the maturation and release of an egg.

      There’s a characteristic pattern of ovarian enlargement to 1.5 to 3 times normal size, and a number of small cystic structures of less than 10 mm, which are usually located in a circle around the ovarian surface, commonly called a ‘string of pearls’.

      DOES PCOS MEAN I HAVE OVARIAN CYSTS?

      Ovarian cysts are a common but usually unrelated gynaecological disorder. They differ from polycystic ovaries in that they 1) are typically found within the ovary 2) they occur singly and not in groups and 3) can, if left untreated, become cancerous. Polycystic ovaries, on the other hand, are neither cancerous nor are they likely to become so.

      WHAT CAUSES PCOS?

      PCOS continues to perplex even the medical experts⁷ who specialize in it. We know that there’s a very strong genetic and hereditary basis of PCOS,⁸ but even if two women have the same gene they may end up with different symptoms, depending on their environment and lifestyle.

      TIME FOR A NAME CHANGE?

      As the ‘cysts’ in PCOS aren’t actually cysts at all, and because a woman who’s had her ovaries removed can still have PCOS symptoms, some scientists are calling for a name change for the condition – if the underlying metabolic condition affects your ovaries, then your ovaries aren’t the cause and shouldn’t be the main focus of the name.

      ‘Polyfollicular syndrome’ has been suggested, as have ‘ovarian dysmetabolic syndrome’, ‘Syndrome O’, ‘cystic ovaries’, ‘functional hyperandrogenism’, ‘Stein-Leventhal syndrome’ and ‘chronic anovulation’.

      It’s fantastic that the condition has become a talking point among medical specialists, and while PCOS may be an imperfect name, whatever the syndrome is eventually called, it matters most that it’s recognized, evaluated and treated.

      The effect of environment and lifestyle is also clear because you can have polycystic ovaries (PCO) without having the syndrome (PCOS).

      With pelvic ultrasound it has been found that approximately 20–30 per cent of women of reproductive age will have polycystic ovaries, but only about half of these will have the signs or symptoms of PCOS. If the otherwise ‘normal’ group is examined closely, experts⁹ believe they may be experiencing the subtle hormonal changes associated with PCOS, but just have them under control, perhaps due to diet, exercise and lifestyle factors. But women with PCO are thought to be predisposed to develop PCOS if those lifestyle factors change, and if they do it could have a significant impact on their long-term health, such as an increased risk of diabetes and heart disease.

      It’s also possible to have PCOS symptoms but not have polycystic ovaries on a scan. This makes sense if you think that the ovarian changes are just another symptom of the underlying cause of PCOS – which we’ll talk about in the next chapter.

      ‘When I was finally diagnosed with PCOS the relief was incredible. Knowing what is wrong with me gives me choices.’

       Susan, 38

       CHAPTER 2 WHAT CAUSES PCOS?

      The search for the underlying cause of PCOS is ongoing. Here’s what researchers have uncovered so far.

      IT’S ALL IN THE GENES!

      Researchers have noticed that PCOS tends to run in families, and a number of studies¹ suggest that genes play a part in developing the syndrome. A gene is a basic unit of heredity; bits of DNA that direct the reproduction, growth and function

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