Contrary to its name, polycystic ovary syndrome is not simply an ovarian condition—it’s a multi-system disorder that affects reproductive, metabolic, and mental health, says Professor Helena Teede, Director of the Monash Centre for Health Research Implementation, endocrinologist at Monash Health, and a lead author of the International PCOS Guideline.
Like type 1 diabetes, PCOS is a polygenic inherited condition. Genetic predisposition interacts with environment—particularly weight gain—to drive clinical expression.
In our increasingly obesogenic environment, we’re seeing PCOS “manifest and increase in prevalence in more people who have otherwise got a milder genotype,” she said in a recent Healthed podcast.
Most women with PCOS are hyperinsulinaemic and hyperandrogenic, with underlying neuroendocrine dysfunction, she explained.
Weight gain exacerbates hormonal dysregulation, creating a self-perpetuating loop that worsens insulin resistance and hyperandrogenism and sustains ovulatory dysfunction.
Importantly, there are no true ovarian “cysts” in PCOS, and the condition is being renamed to better reflect its pathophysiology.
“There’s nothing actually wrong with the follicles; they are just arrested in development. They don’t like the hyperandrogenic, hyperinsulinaemic environment they’re in,” Professor Teede said.
Women with PCOS are at heightened risk of cardiometabolic conditions, endometrial hyperplasia and malignancy, infertility, and psychological issues—including markedly higher rates of depression and anxiety, eating disorders, psychosexual dysfunction, and suicide attempts.
They typically start diverging from the healthy weight range by the age of six and have higher lifetime rates of weight gain. Nearly all women with PCOS (95-100%) who have a BMI over the healthy weight range—and 75% to 85% of those who are lean—meet WHO criteria for insulin resistance, Professor Teede said.
All women with PCOS need their glucose profile monitored regularly (every one to three years, depending on risk factors), and a single insulin test is “useless,” she stressed.
Oral glucose tolerance testing (OGTT) is the most accurate test of glycaemic status in PCOS, irrespective of BMI. Fasting glucose or HbA1c are alternatives if OGTT is not feasible.
Lipids only need testing at diagnosis unless the patient has significant cardiometabolic risks, she added.
Every woman should undergo mental health screening.
About 50% of affected women are not diagnosed until they need infertility treatment, Professor Teede said.
“What happens is they present with symptoms in adolescence, they are not diagnosed, they’re usually put on the combined oral contraceptive pill and they go away. And all the other features of the condition are not monitored or treated.”
After stopping contraception, they may not know they are at increased risk of infertility, leading to delayed referral, smaller than intended family size and higher rates of nulliparity, she said.
Symptom burden, poor information, stigma and delayed care underpin much of the psychological distress.
In adults, you can diagnose PCOS after excluding other causes if they have two of the following:
You only need to do a free androgen index and total testosterone when there are no clear clinical features of hyperandrogenism, Professor Teede said. “You do not need to do DHEAS and androstenedione.”
Ultrasound is only needed for diagnosis in about 30% of cases, she added.
“They’re expensive, inconvenient, often inconsistently or poorly reported. And the number of women who come to me saying I’ve got PCOS, I’m not going to have a family, and all they’ve got is PCOM—but the report said they had polycystic ovary syndrome—it often causes more harm than good.”
Associate Professor Anju Joham, consultant endocrinologist at Monash Health and lead of the PCOS epidemiology research group at the Monash Centre for Health Research and Implementation, said an ultrasound may be helpful if there are other symptoms, such as menorrhagia or severe dysmenorrhea.
To exclude alternative diagnoses, check thyroid function, prolactin, 17-hydroxyprogesterone and FSH.
Adolescents must have both hyperandrogenism and irregular cycles, defined as:
Neither ultrasound nor AMH testing are recommended for adolescents.
If only one criterion is present, describe them as “at risk of PCOS”, treat symptoms, and reassess after age 20.
What if they are on the pill already?
You can diagnose retrospectively from a clear history of irregular cycles and hyperandrogenism, Professor Teede said. Otherwise, the pill needs to be stopped for at least three months.
Limiting weight gain throughout life supports better outcomes, but there is no miracle diet for PCOS, Professor Teede stressed.
“It is whatever the healthiest diet is that works for them.”
GLP-1 receptor agonists can promote weight loss, but caution is required in women planning pregnancy.
“The moment you come off these agents your weight goes up. We’re starting to see documented cases of 30-kilogram weight gain in pregnancy, which can be quite devastating in terms of its health impacts,” she warned.
Metformin does not induce weight loss but helps prevent weight gain and diabetes, Professor Teede said.
The guideline advises considering metformin to improve metabolic and anthropometric outcomes in adults with PCOS who have a BMI of 25 or more. You can also consider it for adults with a BMI of less than 25, and for cycle regulation in adolescents with or at risk of PCOS—although there is limited evidence for these applications.
They suggest starting at a low dose and increasing in 500 mg increments every one to two weeks to a maximum of 2.5 g daily in adults (2 g in adolescents). Slow-release formulations may improve tolerability.
Metabolic/bariatric surgery shows promise, Professor Teede says, noting that while it carries risks in pregnancy, it can also confer substantive benefits.
For example, a randomised controlled trial published in The Lancet demonstrated a “normalisation of a lot of the features of the condition and complete return to normal ovulation” in a group of women with PCOS, obesity and oligo/amenorrhea who underwent bariatric surgery.
“It’s likely we will move to increasingly strong recommendations about the role of obesity medication and metabolic surgery in PCOS,” she said.
“From the time they’re diagnosed, these women need a reproductive life plan,” Professor Teede said.
She advises considering a woman’s likely prognosis before referring her for fertility management.
“If they’re 28, don’t have a particularly high BMI, and only want two children, it’s quite reasonable for you to start them on metformin, give them some time and see how they go. It’s cheap, doesn’t need monitoring, it works. However, its efficacy is much lower than the other agents.”
“If they want more children, they’re older, they’ve got other risk factors, a higher BMI—refer them earlier.”
While women are increasingly turning to IVF “because it looks like a simple, effective treatment” for fertility issues, it’s often not necessary, Professor Teede said.
“For the vast majority, the first line recommendation after diagnosis and screening is letrozole. It is simple, it is effective, very few people need additional therapy.”
“Occasionally they might need gonadotropins. IVF is third line therapy: higher risk, higher efficacy, higher cost.”
Every woman should undergo preconception cardiometabolic risk and mental health screening, she added.
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