Should SNOMED CT adopt "Polyendocrine Metabolic Ovarian Syndrome" (PMOS) as the new name for polycystic ovary syndrome?

SNOMED Groups Content Managers AG
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A landmark article published in The Lancet on 12 May 2026 (Teede et al.) proposes renaming polycystic ovary syndrome (PCOS) to polyendocrine metabolic ovarian syndrome (PMOS), following a rigorous, multistep global consensus process. The new name reflects the condition’s polyendocrine, metabolic, and ovarian pathophysiology, removes the misleading reference to ovarian cysts, and has been widely welcomed by both the clinical community and patient advocates. Notably, the authors explicitly name SNOMED CT as a target system for adoption as part of a planned three-year global implementation strategy.

This raises a direct question for our community: should SNOMED CT adopt PMOS, and if so, how?

The question is not purely one of naming. The current SNOMED CT concept for PCOS is modelled as an ovarian disorder. PMOS, by definition, is a polyendocrine metabolic condition that extends well beyond the ovary. This means that simply renaming the existing concept would constitute a change in meaning — which under SNOMED editorial principles requires inactivation and replacement with a correctly modelled new concept, not merely a description update. The downstream impacts on value sets, maps, and coded patient data would need careful management.

Possible approaches include:

  1. No change yet — monitor clinical and ICD uptake before acting

  2. Add PMOS as a synonym now — with preferred term status and remodelling deferred to a defined milestone such as ICD adoption or the 2028 International Guidelines update

  3. Inactivate the existing concept and create a new correctly modelled PMOS concept — the editorially rigorous path, with PCOS retained as a historical synonym and appropriate replacement associations provided for implementers

We would welcome community views on the following:

  • Does the robustness of this consensus process justify early action in SNOMED CT?

  • Which approach best balances editorial integrity, implementer impact, and patient benefit?

  • What milestone should trigger full adoption if a deferred approach is preferred?

  • Should PCOS be retained indefinitely as an acceptable synonym or deprecated over the transition period?

Please share your perspectives below.

2 Likes
Name change from Polycystic Ovarian Syndrome to PMOS
Exploring a move from PCOS to PMOS
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Hi Jim,

I shared the US NRC response in the MF Forum post, but will share it here for the CMAG as well:

We recommend Option #2, which adds PMOS as a synonym now. Once the new PMOS concept is created, PCOS should be inactivated, as you have already noted, because the condition’s underlying definition has changed. This should also include inactivating the PCOS children:

  • PCOS of the left ovary

  • PCOS of the right ovary

  • PCOS of bilateral ovaries.

Thanks,

Nick

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Hi Jim,

We have received change requests from clinicians following the announcement that Polycystic Ovary Syndrome (PCOS) has been renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS).

We support Option 2: adding PMOS as a synonym during the transition period, allowing clinicians to use the updated terminology while clinical guidelines and systems are updated.

I agree with Nick that, following establishment of the new PMOS concept, PCOS and its child concepts should be inactivated to reflect the revised definition.

Thanks