Polycystic ovary syndrome, or PCOS, is one of the most common hormonal conditions affecting women of reproductive age and a common cause of ovulation-related infertility.

Importantly, PCOS does not mean that you cannot have a baby.

Many women with PCOS conceive naturally or with relatively simple fertility treatment.

What Is PCOS?

PCOS is a hormonal and metabolic condition.

Features can include irregular ovulation, increased androgen activity and polycystic ovarian morphology on ultrasound.

Not every woman with PCOS has every feature.

Why Does PCOS Affect Fertility?

The main fertility problem is often irregular or absent ovulation.

If an egg is released infrequently, there are fewer opportunities for conception.

Women may have cycles lasting many weeks or months, making prediction of the fertile window difficult.

PCOS and Metabolic Health

PCOS is also associated with metabolic factors such as insulin resistance in some women.

Preconception care therefore involves more than simply inducing ovulation.

Assessment may include weight, blood pressure, glucose metabolism and other relevant health factors.

Lifestyle Treatment

For women who are above their healthy weight range, modest sustainable weight reduction may improve metabolic health and, in some cases, menstrual regularity.

The focus should be on achievable long-term changes rather than crash dieting.

Regular physical activity, adequate sleep and balanced nutrition are valuable regardless of whether fertility medication is required.

Ovulation Induction

If irregular ovulation is the primary fertility problem and other factors are reassuring, ovulation induction may be considered.

Letrozole is commonly used as a first-line pharmacological ovulation-induction treatment for appropriate women with PCOS.

Treatment should be medically supervised.

The objective is generally to encourage development and ovulation of one follicle rather than producing multiple eggs.

When Is IVF Needed?

Not every woman with PCOS requires IVF.

IVF may be considered when:

• Other infertility factors are present
• Ovulation-induction treatment has not succeeded
• There is significant male-factor infertility
• The fallopian tubes are blocked
• Duration of infertility or age makes IVF appropriate
• Other clinical circumstances favour IVF

PCOS and IVF

Women with PCOS often have a relatively high number of follicles and can respond strongly to fertility medication.

This can produce good egg numbers but also increases the risk of excessive ovarian response and OHSS.

Modern treatment strategies can substantially reduce this risk.

These may include:

• Individualised stimulation doses
• GnRH antagonist protocols
• GnRH agonist trigger when appropriate
• Careful monitoring
• Freeze-all strategies in selected patients

Safety should be prioritised over simply maximising egg numbers.

Does PCOS Affect Egg Quality?

PCOS is a heterogeneous condition, and fertility outcomes are influenced by age, metabolic health and many other factors.

Having many follicles does not automatically mean every egg will fertilise or produce a viable embryo.

Likewise, having PCOS does not mean eggs are inherently incapable of producing a healthy pregnancy.

PCOS and Pregnancy

Once pregnancy occurs, women with PCOS may have increased risks of some pregnancy complications, particularly where additional metabolic risk factors are present.

Preconception optimisation of weight, blood pressure, glucose metabolism and general health is therefore valuable.

The Take-Home Message

PCOS is one of the most treatable causes of ovulation-related infertility.

Treatment should be stepwise and individualised.

For some women, lifestyle optimisation and ovulation induction may be sufficient. Others may require IVF because of additional fertility factors or unsuccessful simpler treatment.

The first objective is to understand why conception is not occurring, rather than assuming that every woman with PCOS requires IVF.