Learn the Different Types of PCOS from a PCOS Nutritionist

PCOS is complex in nature. There are varying degrees of how the condition will look among women including the type or severity of PCOS symptoms including physical symptoms, hormonal changes, or metabolic changes.

While it may be more commonly known to cause infertility for women of reproductive age, there are other manifestations of the condition such as obesity, insulin resistance, type 2 diabetes, metabolic syndrome, fatty liver, and altered blood lipids.

Diagnosing PCOS has evolved over the years, with the last ten years expanding knowledge of the condition exceptionally.

PCOS Diagnosing Criteria

In 1990, the US National Institutes of Health (NIH) was the first to set diagnostic criteria for PCOS. Just two conditions had to be met to diagnose PCOS - high testosterone levels (hyperandrogenism) and an absent or irregular period.

In 2003, the European Society for Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM) expanded the diagnostic criteria to include two of three criteria:

1) high testosterone levels

2) the absence of or irregular menstruation

3) discovering cysts on the ovaries via an ultrasound

In addition to these diagnostic criteria, in 2012 NIH defined the four distinct phenotypes we know today, allowing women for a more specific diagnosis.

In redefining the diagnostic criteria for PCOS over the years to encapsulate more factors, the prevalence worldwide has climbed from 4-6.6% to as high as 21%.

The Four Types of PCOS

There are four different phenotypes:

1. Phenotype A

2. Phenotype B

3. Phenotype C

4. Phenotype D

The severity of the types decreases as you descend from phenotype A to D with the highest severity for phenotype A and lowest severity for phenotype D.

Since a diagnosis of PCOS requires two of three conditions, each phenotype represents a unique combination of diagnostic criteria.

Phenotype A: ‘Classic PCOS’

As phenotype A is the most severe, it encompasses all three diagnostic criteria:

1) high testosterone levels

2) an irregular or absent period

3) the presence of cysts on the ovaries

More than half of published research indicates the presence of this phenotype. Being the most common form, it is also known as ‘Classic PCOS’ and presents the highest hormonal imbalance and health risks.

Some of the characteristics of this type include:

• Menstrual dysfunction is most pronounced - but normalizes with age

• Dysregulation of sugar metabolism - increased insulin levels and higher rates of insulin resistance

• Higher risk for obesity and/or high body-mass index (BMI)

• Higher risk for metabolic syndrome

• Unhealthy fats in the blood - high triglycerides, high ‘bad’ cholesterol, and low ‘good’ cholesterol

• Increased risk for fatty liver

• Highest anti-mullerian hormone levels - because of the presence of many small follicles with PCOS

• High testosterone levels and/or symptoms of high testosterone include acne, excess hair growth on the face or body, and hair loss (female pattern baldness).

Phenotype B: The Other ‘Classic PCOS’

Phenotype B, also called ‘Classic PCOS’, is diagnosed by:

1) high testosterone levels

2) irregular or infrequent periods

It encompasses the same characteristics as listed above for phenotype A with the exception of polycystic ovary morphology:

• Menstrual dysfunction is most pronounced - but normalizes with age

• Dysregulation of sugar metabolism - increased insulin levels and higher rates of insulin resistance

• Higher risk for obesity and/or high body-mass index (BMI)

• Higher risk for metabolic syndrome which is a group of conditions that occur together which increases the risk of developing diabetes heart disease, and stoke.

• Unhealthy fats in the blood - high triglycerides, high ‘bad’ cholesterol, and low ‘good’ cholesterol

• Increased risk for fatty liver

• High testosterone levels and/or symptoms of high testosterone include acne, excess hair growth on the face or body, and hair loss (female pattern baldness).

Interestingly, one study (Kar) found that women with phenotype B had more than double the occurrence of metabolic syndrome (~53% in phenotype B compared to ~20% in phe