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Understanding Fertility Conditions

PCOS (PMOS)

What PCOS (now also called PMOS) is, how it can affect ovulation and how it’s assessed.

  • 2 minread
  • 3sections
  • 2myths checked
  • 3sources

PCOSPMOSpolycystic ovary syndromepolyendocrine metabolic ovarian syndromeandrogensirregular periodsovulation

Concept illustration, not to scale: an ovary in PCOS, with many small follicles (not cysts) in a ring under its surface and none grown large enough to release an egg.
Concept illustration, not to scale: an ovary in PCOS, with many small follicles (not cysts) in a ring under its surface and none grown large enough to release an egg.

Tap to enlarge

Preview for Kara’s review. Educational draft · clinical approval pending.

PCOS (polycystic ovary syndrome) is one of the most common hormonal conditions in women. It is also one of the most misunderstood, starting with its name. In 2026, an international group of experts and patient organisations renamed it polyendocrine metabolic ovarian syndrome (PMOS). The new name reflects that the condition affects hormones and metabolism, not just the ovaries, and that the ovaries don’t actually contain harmful cysts. You’ll still hear “PCOS” for a while, as the change is being introduced gradually.

Kara explains

PCOS isn’t really about “cysts”. The small structures seen on ultrasound are usually follicles that haven’t progressed to ovulation. What matters for fertility is often how regularly ovulation happens.

How PCOS is assessed

An ultrasound appearance is one of the features doctors look at; on its own it isn’t a diagnosis.

In adults, after other causes have been excluded, the 2023 international guideline diagnoses PCOS when two of these three features are present: irregular or absent ovulation; signs of higher androgen (“male-type”) hormones, on symptoms or blood tests; and a polycystic ovarian appearance on ultrasound or a raised AMH. So not every woman with PCOS has all three.

PCOS and fertility

Treatment aims to help the ovary release an egg.

PCOS is the most common cause of irregular or absent ovulation, which can make conceiving take longer. It is very treatable. For women who aren’t ovulating, letrozole is now the medicine usually offered first: in a large trial it led to more live births than clomifene (also spelt clomiphene). In South Africa letrozole is registered for breast cancer, so using it for fertility is “off-label”; your doctor can explain what that means for you. Your doctor will advise what suits you.

More than fertility

PCOS can affect metabolic and emotional health too.

PCOS can affect metabolic and emotional health too. Management is individual, and a healthcare professional can help decide what applies to you.

Myth vs evidence

Myth

“PCOS means you can’t get pregnant.”

Evidence

PCOS can make ovulation less predictable, but it does not mean pregnancy is impossible. Individual circumstances differ.

Myth

“If you have cysts on your ovaries, you have PCOS.”

Evidence

An ultrasound appearance alone isn’t a diagnosis. Assessment looks at a combination of features.

Take to your appointment Ask your healthcare professional
  1. Which features of PCOS apply to me, and how was that assessed?
  2. How can we tell whether I’m ovulating?
  3. Are there other health checks I should have because of PCOS?

Words you may hear

Androgens
A group of hormones, including testosterone, present in both women and men at different levels.
Anovulation
A cycle in which ovulation does not happen.
Polycystic ovarian morphology
An ultrasound appearance with many small follicles.
Kara’s key takeaway

PCOS is a spectrum. Understanding which features apply to you leads to far better conversations than the label alone.

Watch with Kara

Videos on this topic are coming to the channel:

  • PCOS and Fertility Explained
  • What Does PCOS Actually Mean?

See the video schedule

Keep learning

Want the foundations in one place? The free Fertility Starter Guide covers ten things everyone should understand about their fertility.

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Sources 3 studies and guidelines Show the research