PCOS and Fertility: Complete Guide to Getting Pregnant With PCOS

> A note on the name: PCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) in May 2026 by global consensus. The condition, its diagnosis and its treatment are unchanged — only the name. Both terms will be in use for the next few years. We use PCOS below as the more familiar term.

PCOS and fertility: complete guide

Diagnosis

Rotterdam criteria — two of three: irregular or absent ovulation; clinical or biochemical signs of raised androgens; polycystic ovaries on ultrasound.

Update worth knowing: current international guidance accepts a raised AMH as an alternative to ultrasound for the ovarian criterion in adults.

And a caution: ultrasound should not be used for the ovarian criterion within about eight years of a girl's first period — multifollicular ovaries are normal at that age and using the scan leads to over-diagnosis in adolescents.

Note that polycystic-looking ovaries alone do not diagnose PCOS. A substantial proportion of women with no hormonal problem have that appearance.

Fertility treatment

Letrozole should be first-line for ovulation induction in women with PCOS and anovulatory infertility who have no other infertility factors — an evidence-based recommendation. It is preferred over clomiphene because it improves ovulation, clinical pregnancy and live birth rates.

Two practical points: letrozole remains off-label in many countries, and there is no evidence of increased teratogenicity compared with other ovulation induction agents — the concern most often raised against it.

Clomiphene could be used in preference to metformin, though multiple pregnancy risk is increased and ultrasound monitoring may be needed.

Metformin could be used alone — whilst informing women that more effective ovulation agents exist. That clause is part of the recommendation. Its advantage is a lower monitoring, travel and cost burden, which is a legitimate consideration.

Weight

5 to 10% weight loss can restore ovulation without medication. Two things worth saying: weight loss is physiologically harder in PCOS, where insulin resistance with compensatory high insulin is present in 85% of those affected — and PCOS occurs in lean women too.

For IVF

The GnRH antagonist protocol is recommended for predicted high responders, with a reduced dose of 100 to under 150 IU. Dopamine agonists are recommended to reduce early OHSS risk. A GnRH agonist trigger with freeze-all is recommended where OHSS risk is high.

Recommended against: routine metformin with the antagonist protocol, growth hormone, and myo-inositol in PCOS undergoing IVF.

The part that is not about fertility

If your periods are absent for many months at a time, the lining can thicken without shedding, which over years carries a risk of endometrial hyperplasia. Going more than three or four months without a period is worth discussing with your gynaecologist — ensuring the lining sheds is protective, not cosmetic.

Ask also about fasting glucose, HbA1c, lipids and blood pressure. The metabolic risks are more likely to affect you than anything else about PCOS.