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What are the different types of PMOS?

According to the 2012 NIH Evidence-Based Workshop on PCOS, PMOS can be grouped into four sub-types based on the presence of hyperandrogenism, ovulatory dysfunction and/or polycystic ovaries.


PMOS is a complex, multi-system disorder that affects different individuals differently; researchers have identified four different types of PMOS based on core symptoms.[1]

 

In this article we explore four different types or phenotypes of PMOS.

 

The most common type of PMOS, affecting c.70% of individuals with the condition, combines all three diagnostic criteria including androgen excess, ovulatory dysfunction and polycystic ovaries:[2]

  • Androgen excess (AE) (or hyperandrogenism), higher than usual levels of androgens, a type of sex hormone naturally produced in the ovaries and in the adrenal glands located on the top of your kidneys;[3][4]

  • Ovulatory dysfunction (OD), failure to ovulate on a regular cycle leading to irregular or absent periods; and

  • Polycystic ovaries (PCO), the presence of multiple follicles or cysts around the outside of the ovary, often referred to as a “string of pearls”.[5]

 

In addition to these diagnostic criteria, PMOS is associated with:

  • High body mass index (BMI), the ratio of your weight in kilogram divided by the square of your height in meters, with a value higher than 25 or 30 being classified as overweight or obese respectively;[6]

  • High ovarian reserve, an estimate of the number of remaining eggs compared to the average for individuals your age (noting that this is not a measure of quality of the eggs);[7]

  • High fasting insulin, the level of insulin (the natural hormone that turns food into energy)[8] in your bloodstream, with levels greater than 25 milli international units per liter (mIU/L) in a fasting test classified as hyperinsulinemia;[9]

  • High cholesterol in the form of high levels (>150 milligram per deciliter) of low-density lipids (LDLs) and low levels of high-density lipids (HDLs);[10]

  • High levels of anti-Müllerian hormone (AMH),[11] a protein produced by granulosa cells within ovarian follicles and a measure of ovarian reserve;[12] and

  • Higher resistance to clomiphene, failure to ovulate over the course of 3 cycles when treated with clomiphene citrate (CC), the medication commonly used to stimulate ovulation during fertility treatment.[13][14][15]

 

Another c.20% of individuals with PMOS exhibit androgen excess (AE) and polycystic ovaries (PCO) but not ovulatory dysfunction (OD).[16]

 

A further c.10% of individuals with PMOS exhibit androgen excess (AE) and ovulatory dysfunction (OD) but not polycystic ovaries (PCO).[17]

 

The remaining c.5% of individuals with PMOS exhibit ovulatory dysfunction (OD) and polycystic ovaries (PCO) but not androgen excess (AE).

 

Sources 
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310679/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683693/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9541126/
[4] https://my.clevelandclinic.org/health/articles/22002-androgens
[5] https://www.uptodate.com/contents/polycystic-ovary-syndrome-pcos-beyond-the-basics/
[6] https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html
[7] https://my.clevelandclinic.org/health/diagnostics/25142-ovarian-reserve-testing   
[8] https://my.clevelandclinic.org/health/body/22601-insulin       
[9] https://www.verywellhealth.com/hyperinsulinemia-is-associated-with-type-2-diabetes-1087717  
[10] https://www.uptodate.com/contents/high-cholesterol-and-lipids-beyond-the-basics/
[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006968/
[12] https://www.womenandinfants.org/services/medical-screening/amh-test
[13] https://www.jsafog.com/abstractArticleContentBrowse/JSAFOG/10874/JPJ/fullText
[14] https://www.sciencedirect.com/science/article/abs/pii/S2468784717301393
[15] https://my.clevelandclinic.org/health/drugs/19178-clomiphene-tablets
[16] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310679/
[17] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310679/

Want to learn more about how PCOS affects different individuals? Check out the sections on Metabolic vs Reproductive PCOS and PCOS Diagnosis.

Symptoms

Types of PMOS (4 Cluster Model)

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