Weight gain during pregnancy with pregnant woman holding scale.

Polycystic Ovarian Syndrome and fertility

Polycystic Ovarian Syndrome (PCOS) is a relatively common condition of androgen excess and ovarian dysfunction.

It affects 12 to 18% of women of child-bearing age. Importantly, in the context of Western obesogenic environments, prevalence of PCOS increases to one in three for women of child-bearing age who are over-weight or obese.

The aetiology of PCOS is complex, with diverse epigenetic and environmental influences, leading to a characteristically heterogenous expression.

In some women androgen excess is in itself, sufficiently severe to cause PCOS. These women may be underweight or of normal weight yet exhibit PCOS symptoms of hirsuitism, irregular menstrual cycles and infertility.

In other women, the presence of abdominal obesity and insulin resistance may convert a mild androgen excess to overt PCOS accompanied by metabolic dysfunction. This increases the risk of chronic conditions including the metabolic syndrome, heart disease and type 2 diabetes as well as malignancies like breast cancer.

No universal treatment is available for PCOS

Given the diversity of presentation, current recommendations are for individualised treatment, targeted at reducing symptoms and acknowledging that PCOS is a lifelong disorder that is responsive to lifestyle change.

Western-style diets, rich in animal-derived and highly processed foods and fast foods are high in advanced glycation end-products (AGEs). These promote chronic inflammation and may exacerbate symptoms of PCOS. Conversely, emerging evidence suggests that diets high in anti-inflammatory food components may have utility in treatment of PCOS.

Anti-inflammatory measures are best delivered via whole diets rich in a wide variety of plant foods.

Evidence is poor that herbal remedies or vitamin or antioxidant supplements improve fertility.

PCOS, food and fertility

The two key arms of treatment for PCOS are optimising body weight status and blood-glucose control. Weight management can alleviate symptoms, increase insulin sensitivity, increase fertility and decrease the risk of chronic conditions later in life.

Blood glucose control is essential to manage the insulin resistance that exacerbates symptoms of PCOS.

Weight management advice

  • If overweight or obese, achieve weight-loss of 5-10% of body weight. This will increase insulin sensitivity and decrease cardiovascular risk later in life.

  • If a healthy weight, prevent weight gain by consuming a balanced diet and regularly monitoring body weight and waist circumference. Abdominal adiposity in a woman within the normal range of body mass index can trigger PCOS.

  • Hormonal imbalance associated with PCOS predispose women to gain weight and cause symptoms to deteriorate. Trends to weight increase should therefore be addressed sooner rather than later.

  • Encourage, lifestyle and exercise planning, the setting of small achievable goals and where possible garner family and social support.

  • Provide a multi-disciplinary approach to support weight control. This may incorporate behavioral and psychological strategies such as motivational interviewing, self-monitoring, problem solving, time management and relapse prevention.

Diet and lifestyle advice

  • Αs dietary inadequacy increases risk and symptoms of PCOS, the diet of both normal and overweight women should be examined for nutritional adequacy.

  • Provide advice on shopping and home cooking methods to help women reduce consumption of a pro-inflammatory, Western-style diet high in fast foods and refined, sugar-rich carbohydrate.

  • Give advice to help establish a balanced dietary pattern that includes a variety of whole grains, low-fat dairy, lean meat and plant sources of protein, and encourage the consumption of a wide variety of fruits and vegetables.

  • Promote whole diets high in anti-inflammatory food components (such as the DASH diet or the Mediterranean diet).

  • Provide advice on strategies to control portion sizes.

  • Encourage the consumption of mono-unsaturated and poly- unsaturated fats, and limit saturated fat.

  • Review activity levels and encourage women to be physically active on most days (30 to 60 minutes of moderately vigorous physical activity per day).

  • Discourage very heavy exercise programs and over-training (>60 min/day) as this may increase the risk of anovulation.

Blood-glucose control

  • Provide advice to consume small, regular meals throughout the day and to avoid skipping meals. This will ensure that carbohydrates are spread more evenly throughout the day and decrease ‘spikes’ in blood-glucose levels.

  • Promote carbohydrate foods that are high in fibre and which have low-GI. This will allow glucose to be released slowly into the blood-stream. High-fibre food, low GI foods will also leave women feeling fuller for longer which helps to prevent excess food consumption.

  • Metformin, while not a dietary approach to PCOS, may assist with blood-glucose control. Metformin is often used to treat the insulin resistance associated with PCOS.

Changes to diet and lifestyle

Dietary and lifestyle changes can be difficult for women to make without education and ongoing monitoring and support. Knowledge of what constitutes a healthy diet and lifestyle is seldom enough to bring about change.

It is important to consider wider influences affecting women’s decisions.

These may range from economic (is healthy food affordable and available?) to cultural (do they have cooking skills?) to societal (do family pressures and time constraints prevent lifestyle change?). Other influences are broadly political-aggressive marketing of processed foods, or government decisions on parks, footpaths and bike tracks.

Dietitians consider these influences and assist women to implement strategies to make healthy lifestyle choices in the environment in which they live. They can provide women with individualised dietary advice to achieve their health-related goals.

Clinical practice guidelines

Earlier this year Australian National Health and Medical Research Council, partnering with European Society of Human Reproduction and Embryology and American Society for Reproductive Medicine, released an International evidence-based guideline for the assessment and management of polycystic ovarian syndrome.

It builds on previous guidelines, providing health professionals with comprehensive guidance for screening, diagnosis, lifestyle advice, pharmacological treatment, and assessment and treatment of fertility for women with PCOS. Jean Hailes also offers additional resources for health professionals and advice for women.

Practice points

Go to Downloads to access a further evidence behind these recommendations that you may apply to your practice.


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