PCOS and trying to conceive: what you actually need to know

Polycystic ovary syndrome (PCOS) is one of the most common hormonal conditions affecting women of reproductive age, affecting roughly 1 in 10. It's also one of the most common causes of irregular ovulation, which is why it comes up frequently in fertility contexts. But PCOS is often poorly explained, and the name itself is somewhat misleading.

What PCOS actually is

PCOS doesn't mean the ovaries are "polycystic" in the way a cyst normally implies. The "cysts" are actually small, immature follicles — egg-containing sacs that haven't finished developing and weren't released at ovulation. They're a sign of disrupted ovulation, not a dangerous growth.

The underlying driver is hormonal imbalance, particularly elevated androgens (male hormones like testosterone) and insulin resistance in many cases. This disrupts the normal cycle of follicle development and ovulation. Instead of one follicle maturing and releasing an egg each cycle, multiple follicles partially develop and then stall.

Diagnosis requires meeting two out of three criteria: irregular or absent periods, elevated androgens (either measured in blood or visible as symptoms like acne or excess hair), and the polycystic appearance on ultrasound. You don't need all three.

What this means for fertility

Irregular ovulation is the primary fertility challenge. If you're not ovulating, or only ovulating occasionally and unpredictably, conception is difficult to time. Standard ovulation predictor kits (OPKs) can be unreliable with PCOS because LH (the hormone OPKs detect) can be chronically elevated, making it hard to identify the true surge.

The good news: PCOS doesn't cause infertility per se — it makes ovulation irregular. Once ovulation is restored, fertility outcomes for people with PCOS are generally comparable to those without. The question is how to restore it.

Approaches that help

Weight management. For people with PCOS who carry excess weight, weight loss — even modest amounts (5–10% of body weight) — often restores more regular ovulation. The mechanism is related to insulin sensitivity: reducing insulin resistance reduces androgen production and allows the normal hormonal cycle to resume.

Metformin. Metformin is a diabetes medication that improves insulin sensitivity. It's commonly prescribed off-label for PCOS to restore ovulation and is often used before or alongside other fertility treatments.

Letrozole. Letrozole (an aromatase inhibitor originally developed as a breast cancer drug) is now the first-line medication for ovulation induction in PCOS. It's more effective than the older clomifene for PCOS-related anovulation and has a good success rate.

IVF. For people who don't respond to oral medications, IVF is an option. People with PCOS require careful ovarian stimulation protocols because they're at higher risk of OHSS (ovarian hyperstimulation syndrome).

Diet and lifestyle

A lower glycaemic index (GI) diet — one that avoids spikes in blood sugar — can improve insulin sensitivity and may support more regular ovulation in PCOS. This doesn't require anything extreme: it mostly means favouring whole grains over refined ones, limiting added sugars, and including protein and fat with meals to slow glucose absorption. Exercise independently improves insulin sensitivity as well.