This post was written by one of our contributors; medical student Saskia Craine
We often hear about Polycystic Ovarian Syndrome (PCOS) being a common cause of irregular periods and infertility in women, but what exactly is PCOS?
What is PCOS?
PCOS is a complex hormone disorder which affects approximately between 6 – 10% of women worldwide (1). It is caused by elevated levels of male hormones (called androgens) in women. Signs and symptoms include: irregular or no menstrual periods, acne, hirsutism (excess body and facial hair), difficulty getting pregnant, and the presence of cysts on the ovaries (1,2). It is also associated with some other conditions such as: insulin resistance (which can lead to type 2 diabetes), obesity, heart disease, mood disorders, and endometrial cancer (3).
Though the exact cause of PCOS is not yet understood, it helps to know the basic physiology of the structures involved.

Figure 1: https://www.researchgate.net
The female reproductive system is controlled by hormones released from an area of the brain known as the hypothalamus (Figure 1). Gonadotrophin releasing hormone (GnRH) stimulates a gland to release sex hormones required for growth and function of the reproductive system and normal ovulation – luteinising hormone (LH) and follicle stimulating hormone (FSH). An imbalance of these hormones stimulates androgen secretion (4). High levels of androgens stop ovulation and stimulate hirsutism and acne (1). The exact reason why of these hormone changes occur is not known (5); it has been suggested that it may be due to the ovary itself or the glands that produce the hormones. The hormone changes may also be caused by resistance to insulin (5).
Growing scientific evidence shows PCOS is linked to a defect in insulin signalling. Insulin is a hormone produced by the pancreas to control the amount of sugar in the blood; it helps to move glucose from blood into cells, where it’s broken down to produce energy (5). Insulin resistance means the body’s tissues are resistant to the effects of insulin; to compensate, the body tries to produce more insulin – this results in something called hyperinsulinemia, an excess amount of insulin in the blood (1). It is estimated that between 50 and 90% of women with PCOS have insulin resistance, regardless of their body weight (6, 7). High levels of insulin can lead to weight gain, irregular periods, fertility problems and higher levels of testosterone (5,7).
Who is affected by it?
PCOS is a collection of symptoms, therefore the cause and presentation will be different in everyone (9). A combination of your genes and the environmental aspects of how you live can influence your risk (9). PCOS sometimes runs in families, although specific genes associated with the condition have not yet been identified (5). Nonetheless, if your mother, sister or aunt, have PCOS, your risk of developing it is higher (8).
What are the symptoms?
Acne, hirsutism, period problems, infertility, and obesity or difficulty losing weight are common features (2). The development of excessive hair growth often provokes distress in young women and may make them avoid normal social activities. Women with PCOS have a higher risk of depression and low self-esteem (10). High insulin levels can lead to fatigue and sleep disruption (11). Loss of libido is also common and together with irregular menstrual cycles, can make it difficult to get pregnant. Although PCOS is a common cause of infertility, many women remain undiagnosed (7).
How is it diagnosed?
PCOS can be diagnosed using the Rotterdam criteria (2), which requires 2 out of 3 of the following criteria to be present:
- Absent or infrequent periods
- Evidence of excess androgens (all other causes are excluded)
- Polycystic ovaries found on an ultrasound (large size >10cm3 or multiple small follicles 12 or more <10mm).
How is it treated?
Unfortunately, there is no cure for PCOS, however there are many ways to treat and manage individual symptoms, both through lifestyle adjustments and prescribed medication (9).
Lifestyle changes aimed at normalising body weight can significantly improve symptoms – stay tuned for the second part of this article written by our resident dietitian Maeve on lifestyle management of PCOS.
With regards to medication, the following are often used to manage symptoms: An insulin sensitizer, such as metformin, is a diabetes medication that improves insulin sensitivity and reduces the amount of glucose produced by the body. While metformin is effective, it works best when used in conjunction with lifestyle modifications (9).
Inositol is an over the counter supplement and research shows it may be effective at reducing insulin resistance (9). Smaller studies demonstrate it can improve period regularity, reduces testosterone levels and enhances chances of pregnancy (9).
Infertility and anovulation is usually treated by ovulation induction with clomifene under supervision of a fertility specialist (2). It should be not used for more than six months as it is associated with a risk of multiple pregnancy (twins, triplets,) and women are encouraged to have ultrasound monitoring during treatment (12). Once you are pregnant, there is an increased risk of developing pre-eclampsia (high blood pressure) or having babies prematurely, but this can be managed by regular checks (13).
There are several management options for hirsutism. The main treatments are: hair removal (shaving, waxing, laser), elfornithine (a prescription cream to treat excessive hair growth on the face and under the chin), oral contraceptives and anti-androgen medication. Elfornithine is, however, not suitable for women who are pregnant, breastfeeding or under the age of 19. The last treatment option is the oral contraceptive pill (15).
Restoring regular menstrual cycles is important to protect the endometrium (lining of the uterus) and prevent hyperplasia (abnormal cell growth) (2). This can be achieved using the combined oral contraceptive pill (OCP) or progestin-containing intrauterine device (IUD) in women who do not wish to conceive (2). The OCP, however will not cure the underlying cause of your irregular and when you stop taking the OCP your periods will return to being irregular, unless you have made lifestyle changes (9).
Life can be stressful and stress increases cortisol level which increase insulin and testosterone levels (9). Realistically we cannot remove all the stress from our lives, but we can manage it. As PCOS appears to cause significant emotional distress, self-care is very important and appropriate support may be useful (5). Physical activity is a great way to address self-care and can help you unwind (9).
What are the long-term complications?
Women with PCOS are at risk for several long-term complications including type 2 diabetes, heart disease and endometrial cancer (14). This does not mean having PCOS guarantees you will develop these conditions, however, it is important to have regular check-ups alongside leading a healthy lifestyle. If this is done symptoms are more likely to be managed and long-term risks reduced.
References
(1) Chaudhari N, Dawalbhakta M and Nampoothiri L. LGnRH dysregulation in polycystic ovarian syndrome (PCOS) is a manifestation of an altered neurotransmitter profile. Reproductive Biology and Endocrinology. 2018 16:37
(2) Melville C. Sexual and Reproductive Health at a Glance 2015 Chapter 29 Menstrual problems p102-103
(3) NIH. About Polycystic Ovary Syndrome (PCOS) [accessed 3rd March 2019] https://www.nichd.nih.gov/health/topics/pcos/conditioninfo
(4) Heffner L, Schust D The Reproductive System at a Glance 4th Edition 2014 Chapter 31 Secondary Amenorrhea pp. 70-1
(5) NHS. Cause Polycystic Ovarian Syndrome [accessed 3rd March 2019] https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/causes/
(6) Barber t, Dimitriadis G, Andreu A, Franks S. Polycystic ovary syndrome: insight into pathogenesis and a common association with insulin resistance 2016 Clinical Medicine Vol 16, No 3: 262-6
(7) Morley L, Tang T, Yasmin E, Norman R, Balen A. Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility (Review). Cochrane Database of Systemtic Reviews 2017, Issue 11. Art. No.: CD003053. DOI: 10.1002/14651858.CD003053.pub6
(8) Harding D and Jackson C. Polycystic Ovary Syndrome[online] Patient.info. 2016. Available at: https://patient.info/doctor/polycystic-ovary-syndrome-pro
(9) Mitra A. The Gynae Geek. Harper Collins Publishers; 2019 p.45-47
(10) Bhattacharya S and Jha A. Prevalence and risk of depressive disorders in women with polycystic ovary syndrome (PCOS). Fertility and Sterility. 2010, 94(1), pp.357-359.
(11) Thomas L and Dillion. People with PCOS can totally eat birthday cake. Don’t Salt My Game. London; Laura Thomas PhD; 2018; March 28th 2018 [accessed 27th January 2019]. Available from: http://www.laurathomasphd.co.uk/podcast/pcos/
(12) Harding D. Polycystic Ovary Syndrome. Symptoms and treatment. [online] Patient.info. 2016. Available at: https://patient.info/health/polycystic-ovary-syndrome-leaflet
(13) NaturesBest. Pregnancy Complications and PCOS: What You Need to Know. [accessed 3rd March 2019] https://www.naturesbest.co.uk/pharmacy/polycystic-ovary-syndrome/pregnancy-complications-and-pcos-what-you-need-to-know/
(14) Lewandowski K, Cajdler-Łuba A, Salata I, Bieńkiewicz M, Lewiński.The utility of the gonadotrophin releasing hormone (GnRH) test in the diagnosis of polycystic ovary syndrome (PCOS) 2011 A Polish Journal of Endocrinology. Volume 62, Number 2
(15) NHS. Overview: Hirsutism [Accessed 6th March 2019] https://www.nhs.uk/conditions/hirsutism/