What is the difference between polycystic ovary and PCOS?

By (gynecologist), (embryologist), (gynecologist), (embryologist) and (psychologist).
Last Update: 03/08/2022

In our society, it is very common to confuse the presence of polycystic ovaries with the polycystic ovarian syndrome (PCOS). This association is completely misleading, as the two conditions have very different origins and consequences.

Moreover, the risks and treatment options for polycystic ovaries and PCOS are different. It is therefore essential to establish a good diagnosis in order to proceed in the best way in each situation.

Is 'polycystic ovaries' the same as 'PCOS'?

Absolutely not. These situations are totally different despite the fact that in both the fact that the woman has polycystic ovaries occurs.

It is important to briefly introduce what each of these conditions consists of before establishing the main differences between PCOS and polycystic ovary.

What do we mean by 'polycystic ovary'?

An ovary with a polycystic appearance is characterized by the presence of 8 or more follicles in basal conditions. In other words, those women who have more than 8 follicles in the menstruation phase will present polycystic ovaries.

El tamaño de estos folículos suele oscilar entre 2 y 9 mm y se encuentran en estado de reposo, es decir, no están creciendo. Esto hace que se atrofien y formen los llamados quistes que caracterizan esta condición.

What is PCOS?

Polycystic ovary syndrome, popularly known as SOP, is a pathology characterized by altering both the reproductive system as well as the endocrine and/or hormonal system of women. This syndrome produces alterations in various hormones that have a negative impact on the patient's fertility.

The presence of polycystic ovaries is one of the most common symptoms of this syndrome, hence both situations can be confused. However, polycystic ovaries are not the only sign of PCOS. For example, high levels of anti-Müllerian hormone (AMH), excess hair, menstrual irregularities, etc. are also associated with PCOS.

If you want to read more information about this alteration, you can visit the following article: Polycystic Ovarian Syndrome.

How are PCOS and polycystic ovary different?

Although PCOS and polycystic ovaries share the characteristic of presenting polycystic-looking ovaries, these two conditions differ in such important aspects as:

  • Origin.
  • Symptoms.
  • Implications in fertility.

We proceed to discuss these differences in more detail below.

What causes them?

Possessing ovaries with a polycystic appearance is considered to be one more gynecological characteristic of the female reproductive system. There is, therefore, no explanation as to why ovaries have this appearance, but rather their origin is determined by the woman's own genetics without being a pathological condition.

In the case of PCOS, after years of research, it has been discovered that there is a very important genetic implication, given that a series of genes have been found whose alteration could explain the origin of this pathology. It is also known that there is a strong influence of women's lifestyle, especially in relation to food and health habits. However, the main cause of PCOS remains diffuse.

PCOS is a very heterogeneous pathology and not all symptoms are always present with the same degree of affection. This makes diagnosis very difficult.

If you want to know what possible explanations exist to justify the origin of this syndrome, follow this link: What Are the Causes of PCOS?


Women with polycystic ovaries are usually asymptomatic. One of the few symptoms that polycystic ovaries can cause is the alteration of menstrual cycles, causing them to be a little longer.

Normally, this situation does not generate major hormonal and/or reproductive alterations for which it is necessary to visit a gynecologist. Therefore, the diagnosis of polycystic ovaries is usually made spontaneously when the woman goes for a routine check-up.

With regard to PCOS, there is a clinical picture with many hormonal imbalances that can cause:

Absent menstrual period or too sparse and/or sporadic periods.
Clinical and/or biochemical hyperandrogenism
Elevated levels of male hormones in blood, as well as hirsutism (hair that commonly appears in a male pattern in women) and excessive acne.
Excess body fat.
Polycystic ovaries
The ovaries contain multiple follicles in a resting state that causes them to have a necklace pattern.

Given that these symptoms are more obvious, it is not diagnosed by chance during routine visits. Indeed, problems caused by PCOS cause the woman to visit her doctor on purpose.

Reproductive problems

The reproductive problems that these two situations can cause are very different. Below, we discuss the main differences.

Fertility in polycystic ovary

As mentioned above, presenting ovaries with a polycystic appearance does not have to affect the hormonal system and, with it, a woman's fertility.

However, sometimes certain menstrual disturbances may occur that make it difficult to achieve pregnancy. The most commons are:

Due to the high number of follicles that grow in their ovaries, these women may have menstrual cycles without ovulation.
This menstrual alteration supposes presenting cycles of 35 days or more. This makes it very difficult to determine which day ovulation occurs if any, and which days are best suited to conceive.

These problems are easily solvable with ovulation-inducing treatments that allow you to regulate your cycles and achieve pregnancy naturally. These treatments consist of increasing the production of hormones that stimulate the growth of the follicles. Normally, they are usually administered orally for 4 or 5 days and are quite affordable at an economic level.

Sometimes, it may be necessary to carry out ultrasound checks to better control the moment of ovulation and the timing of sexual intercourse.

Fertility in PCOS

As for PCOS, there is a direct relationship with infertility due to the hormonal alterations that this syndrome entails.

High levels of androgens in the blood prevent follicular development from occurring correctly. Not being able to complete their maturation, the follicles cannot release the ovum and remain atrophied in the ovary. This situation can be considerably aggravated by the imbalance of other hormones such as LH or insulin, whose excessively high levels also contribute to preventing ovulation and altering the quality of the oocytes.

Normally, it is necessary to resort directly to stimulation treatments with gonadotropins, which are applied by injection, since ovulation inducers are not enough. This implies the need for greater control through ultrasound and hormonal tests.

In PCOS, the required fertility treatments are more aggressive since the clinical picture involves more serious alterations.

Depending on the degree of severity of the syndrome, as well as the quality of the semen sample used, scheduled intercourse or artificial insemination, or even IVF/ICSI can be considered.

If you need to undergo IVF to become a mother, we recommend that you generate your Fertility Report now. In 3 simple steps, it will show you a list of clinics that fit your preferences and meet our strict quality criteria. Moreover, you will receive a report via email with useful tips to visit a fertility clinic for the first time.

FAQs from users

What criteria are used to diagnose PCOS?

By Mónica Aura Masip M.D., M.Sc. (gynecologist).

Polycystic ovary syndrome (PCOS) is characterized by infrequent or absent periods (oligoanovulation), clinical or analytical hyperandrogenism, and characteristic ultrasound morphology of the ovaries.

These patients may also have difficulty becoming pregnant as ovulation does not occur each month; and they can develop metabolic problems (insulin resistance, hypertension, obesity, increased cardiovascular risk...).

Several expert meetings have been held to agree on the criteria that will define the SOP. Already in 2003, in Rotterdam, it was determined that patients should meet 2 of these 3 criteria:

can manifest with acne, alopecia or hirsutism (increased hair in areas such as the chin, mustache, abdomen, back,...) or increased androgens in the blood.
means ovulating little or never, that will produce irregular or absent periods.
Ovaries with PCOS morphology
Using an ultrasound it is possible to know how big they are and what the ovaries are like. An ovary is considered to have polycystic morphology when it measures more than 10 cc or if it has more than 12 antral follicles, although these limits are still under discussion.
Imagen: diagnostic-criteris-pcos

These criteria would not be valid for an adolescent since at puberty, physiologically, there is an increase in androgens, acne appears, and the ovaries are indistinguishable from a patient with PCOS in most cases.

In order to make an accurate diagnosis, we must allow a minimum of 5 years from the age of the first menstrual period.

Is it advisable to perform AI in women with polycystic ovaries?

By Guillermo Quea Campos M.D. (gynecologist).

Polycystic or multicystic ovaries are those that have several follicles and it is important to distinguish them from polycystic ovary syndrome (PCOS), since they are different alterations.

In the case of women with polycystic ovaries, it is possible that there is some alteration in menstruation and difficulty in releasing the egg, that is, for ovulation to occur. This is why a controlled ovarian stimulation can be performed, regulating ovulation and scheduling the performance of the artificial insemination (AI) cycle.
Read more

My ovaries have a polycystic appearance, can it turn into PCOS?

By Victoria Moliner BSc, MSc (embryologist).

Having polycystic ovaries does not mean that you will end up developing Polycystic Ovary Syndrome (PCOS) in the future. Nonetheless, if you develop other types of hormone irregularities, you are more likely to develop PCOS.

Simply put, the fact that your ovaries have multiple follicles does not mean you are going to have PCOS by default.

My ovaries are plenty of cysts, does it mean I am less fertile?

By Victoria Moliner BSc, MSc (embryologist).

To determine if the presence of multiple cysts is affecting your fertility, you need to visit a doctor to run a series of tests: a blood test to check your hormone levels, as well as a physical exploration to look for potential signs of hyperandrogenism.

Is there any way to differentiate polycystic ovaries from PCOS?

By Victoria Moliner BSc, MSc (embryologist).

To differentiate between these two situations, it is necessary to perform a series of simple medical check-ups: a blood test to check hormone levels, as well as a physical examination to determine if the woman has any clear signs of hyperandrogenism.

The treatment options available to solve the symptoms associated with these situations are very different. With PCOS, women are prescribed medications to try to regulate hormonal levels, while this action is unnecessary with PCO. Want to learn more about the treatment for PCOS? Click here: Treatment of Polycystic Ovary Syndrome.

As explained above, in case you have PCOS and want to have a baby, the fertility treatment recommended for you depends on the severity level of your case. In most cases, ovarian stimulation is needed. To get more info about it, see also: Ovarian Stimulation Protocols for IVF – Process & Medications Used.

To dismiss the possibility that a woman with multiple ovarian cysts has PCOS, she should visit her OB/GYN to undergo a series of diagnostic tests. Learn more about the tests required to assess your fertility here: Female Fertility Tests – How Do You Know if You Can’t Get Pregnant?

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Clayton RN, Ogden V, Hodgkinson J et al. 1992 How common are polycystic ovaries in normal women and what is their significance for the fertility of the population. Clinical Endocrinology 37, 127–134.

Eden JA 1988 Which is the best way to detect the polycystic ovary? Australian and New Zealand Journal of Obstetrics and Gynaecology 28, 221–224.

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Syndrome. Cambridge University Press 2000;56-69.

FAQs from users: 'What criteria are used to diagnose PCOS?', 'Is it advisable to perform AI in women with polycystic ovaries?', 'My ovaries have a polycystic appearance, can it turn into PCOS?', 'My ovaries are plenty of cysts, does it mean I am less fertile?' and 'Is there any way to differentiate polycystic ovaries from PCOS?'.

Read more

Authors and contributors

 Guillermo Quea Campos
Guillermo Quea Campos
Guillermo Quea, MD has a degree in Medicine and Surgery from the University of San Martin de Porres. He also has a Master's Degree in Human Reproduction from the Universidad Rey Juan Carlos and another in Public Health and Preventive Medicine from the Universidad del País Vasco. More information about Guillermo Quea Campos
Member number: 282860962
 Marta Barranquero Gómez
Marta Barranquero Gómez
B.Sc., M.Sc.
Graduated in Biochemistry and Biomedical Sciences by the University of Valencia (UV) and specialized in Assisted Reproduction by the University of Alcalá de Henares (UAH) in collaboration with Ginefiv and in Clinical Genetics by the University of Alcalá de Henares (UAH). More information about Marta Barranquero Gómez
License: 3316-CV
 Mónica  Aura Masip
Mónica Aura Masip
M.D., M.Sc.
Dr. Mónica Aura has a degree in Medicine and General Surgery from the Autonomous University of Barcelona (UAB). She is also a specialist in Gynecology and Obstetrics from the Hospital de Santa Creu y Sant Pau and has a Master's degree in Human Assisted Reproduction from the University Juan Carlos I of Madrid and another in Health Center Management from the UB. More information about Mónica Aura Masip
Licence number: 31588
 Victoria Moliner
Victoria Moliner
BSc, MSc
Degree in Biochemistry and Biomedical Sciences from the University of Valencia (UV). Master's Degree in Biotechnology of Human Assisted Reproduction from the UV and the Valencian Infertility Institute (IVI). Presently, she works as a Research Biologist. More information about Victoria Moliner
Adapted into english by:
 Cristina  Algarra Goosman
Cristina Algarra Goosman
B.Sc., M.Sc.
Graduated in Psychology by the University of Valencia (UV) and specialized in Clinical Psychology by the European University Center and specific training in Infertility: Legal, Medical and Psychosocial Aspects by University of Valencia (UV) and ADEIT.
More information about Cristina Algarra Goosman
Member number: CV16874

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