What Is PCOS or Polycystic Ovary Syndrome?

By (gynecologist), (gynecologist), (embryologist), (embryologist) and (fertility counselor).
Last Update: 09/25/2020

Polycystic Ovary Syndrome or Polycystic Ovarian Syndrome (PCOS), also known as Stein-Leventhal Syndrome, is a common endocrine disorder that can affect female fertility severely.

The symptoms of PCOS are varied and often undetectable until the woman visits her doctor because she has been able to get pregnant despite having tried to conceive for a long time. For this reason, some women with PCOS require a fertility treatment to have a baby.


Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in women of childbearing age, affecting 4-8% of them. It is often associated with:1ß

  • Anovulation (absent ovulation) and subsequent sterility. In fact, it is the most frequent cause of anovulatory infertility
  • Obesity
  • Hyperandrogenism (excessive amount of male hormones)
  • Insulin resistance

Women with PCOS produce higher amounts of androgens than normal, and therefore the menstrual cycle is not regulated correctly. The ovary fails to release eggs because they do not mature, causing cysts. Due to this absent maturation and egg release process, women with PCOS have infertility problems.

Fertility treatments, like any other medical treatment, require that you trust the fertility specialists that will be by your side during your journey. Logically, each clinic has a different work methodology. Our Fertility Report will offer you a selection of recommended clinics, that is, fertility centers that have passed our rigorous selection process. Moreover, our system is capable of comparing the costs and conditions of each one so that you can make a well-informed decision.

PCOS is due to metabolic causes, and it should not be be confused with polycystic ovaries or PCO, which are due to an alteration within the ovarian function, in which follicles are not fully mature and, therefore, they do not release the egg. Follicles then turn into a cyst within the ovarian cortex, which appears thickened in the ultrasound.

Between 16 and 25 percent of women of childbearing age have polycystic ovaries, which does not mean they have PCOS by default. In other words, having polycystic ovaries does not automatically translate into PCOS.

The causes of PCOS are still unclear, although there seems to have a genetic origin. In fact, some studies suggest the involvement of several genes. Most experts consider that it is due to multiple factors, with influence of both genetic and environmental aspects.


Ever since PCOS was described for the first time, the diagnostic criteria used have changed as more information on this syndrome have been discovered.

Presently, the Rotterdam criteria are the most commonly used to diagnose a woman with PCOS. According to them, in order for PCOS to be diagnosed, it is necessary for the patient to present at least two of these symptoms after having dismissed other pathologies:

  • Oligoovulation or anovluation: the patient ovulates less frequently than normal or ovulation is absent.
  • Clinical or biochemical signs of hyperandrogenism
  • Ultrasound scan shows polycystic ovaries: twelve or more follicles of between 2 and 9 cm in corona radiata shape or with an enlarged ovarian volume (over 10 ml) in one or both ovaries are found.

You may also enjoy some further information reading this: How Is PCOS Diagnosed?


Women suffering from PCOS usually experience the following clinical signs:

  • Menstrual irregularities: oligomenorrhea (less than 9 menses per year) or amenorrhoea (absent menstrual period)
  • Anovulatory infertility
  • Hirsutism or excessive amounts of dark, course hair
  • Alopecia or hair loss
  • Acne
  • Hormonal disorders: elevated testosterone levels, high LH levels, elevated LH/FSH relationship, elevated δ4-androstendione (androgen) levels, etc.
  • Increased AMG (anti Müllerian hormone) levels
  • Insulin resistance
  • Polycystic ovaries
  • Breast and uterine hypoplasia
  • Obesity.
  • Acanthosis nigricans: dark patches of skin which usually appear on the neck or the armpits.

The signs and symptoms of PCOS are often aggravated in women with a higher than normal body mass index (BMI).


In cases of predisposition to develop PCOS, changing your lifestyle and following a balanced diet are essential steps against it. Having a BMI-number below 25 and taking contraceptives and antidiabetic drugs is highly advisable, too. It is not only fundamental to avoid obesity but rather a sedentary lifestyle.

Metformin, an antidiabetic drug, has been widely used for the desensitization of the ovaries towards excess insulin, this way promoting follicular development.

In case these women wish to have children, especially in obese women, the first step to making this dream come true will be to establish healthier lifestyle habits. If this is not enough, or if losing weight is not necessary, ovulation will be induced artificially with fertility drugs such as Clomid.

When these strategies fail, patients have no alternative but to turn to Assisted Reproductive Technology (ART). In some cases, undergoing just an IUI works, but in other cases, the patient might require In Vitro Fertilization (IVF) to achieve pregnancy.

Related content: Treatment Options for PCOS.


As Dr. Miguel Ángel Vincenti Bosco explains, PCOS is one of the most common endocrine disorders in females. In fact, it is present in 4 to 8 percent of women who visit a fertility clinic. PCOS disease has important consequences on the woman affected from the obstetric, metabolic, and psychological viewpoints.

From the obstetric point of view, it increases the number of risks during pregnancy. For example, these patients are more likely to have recurrent miscarriage or develop a disease such as toxemia of pregnancy (gestosis), diabetes or high blood pressure during pregnancy, Dr. Vincenti Bosco states.

As for the metabolic effects, PCOS patients are usually women with a BMI that is higher than normal, in some cases with morbid obesity. Also, these women typically have hirsutism, increased body hair in places that are more common in males, insulin resistance, and hyperandrogenism.

FAQs from users

What are my chances of getting pregnant with IUI if I have PCOS?

By Carmen Ochoa Marieta M.D., Ph.D., M.Sc. (gynecologist).

The success rates of Intrauterine Insemination (IUI) depend on the type of insemination (by husband or by donor), the age of the woman, and the problem she has. On average, success rates range from 14% to 20% per cycle.

Can PCOS be cured?

By Rebeca Reus BSc, MSc (embryologist).

The fact that there are genetic factors involved makes it more difficult for this disorder to be cured. However, it can be prevented or its symptoms diminished if the woman leads a healthy lifestyle and controls her diet.

Can metformin help you get pregnant with PCOS?

By Rebeca Reus BSc, MSc (embryologist).

Metformin can help to resume ovulation cycles, achieving normal cycles in obese patients with insulin resistance. Nonetheless, if this is the only drug administered, the clinical success rates do not seem to increase. Metformin just seems to provide a series of benefits for women with PCOS who are trying to get pregnant and are using clomiphene citrate as well, such as Clomid.

Does PCOS run in the family?

By Marta Barranquero Gómez B.Sc., M.Sc. (embryologist).

No. Polycystic ovary syndrome (PCOS) is an endocrine disorder whose cause is unknown. It is true that there is a genetic predisposition and there are several genes involved,

However, according to the latest studies, PCOS has a multifactorial origin where both genetic and environmental factors intervene.

What treatment options can help you get pregnant with PCOS?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

The best treatment option depends on the results of your hormone analyses and the gynecological examination. Firstly, you can try with a change in lifestyle habits, which can be helpful to regulate the menstrual cycle. If this does not work to overcome anovulation, you may be prescribed a series of drugs to induce ovulation. Finally, if none of these treatment options work, you may be required to undergo a fertility treatment, such as IUI or IVF, if needed.

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Adams Hillard PJ. Oral contraceptives and the management of hyperandrogenism - polycystic ovary syndrome in adolescents. Endocrinol Metab Clin N Am 2005; 34:677-705.

Asunción M, Calvo RM, San Millán JM, Sancho J, Ávila S, Escobar-Morreale HF. Prospective study of the prevalence of the polycystic ovary syndrome in unselected Caucasian women from Spain. J Clin Endocrinol Metab. 2000;85: 2434-8.

Bajares de Lilue M, Pizzi R, Velázquez Maldonado E. Tratamiento del síndrome de ovario poliquístico. Manejo dermatológico. Caracas: Editorial Ateproca. 2007: 67-71; 80-84.

Checa Vizcaíno, M.A., Espinós Gómez, J.J., Matorras Weining, R. (2005). Síndrome del ovario poliquístico. Buenos Aires; Madrid: Médica Panamericana. Sociedad Española de Fertilidad (SEF). ISBN 84-7903-599-4

ESHRE/ASRM Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome. Fertil Steril 2004; 81:19-25

Griesinger G. y col. (2006). GnRH-antagonists in ovarian stimulation for IVF in patients with poor response to gonadotropins, polycystic ovary syndrome, and risk of ovarian hyperstimulation: a meta-analysis. Reproductive BioMedicine Online; 13: 628-638.

Huddelston HG (2013). Biomarkers of ovarian reserve in women with polycystic ovary syndrome. Semin Reprod Med.

Moll E, van der Veen F, van Welly M. The role of metformin in polycystic ovary syndrome: a systematic review. Hum Reprod Update 2007; 13(6):527-37.

Reproducción Asistida ORG. Video: Sindrome del Ovario Poliquístico (Polycystic ovary syndrome), by Miguel Ángel Vincenti Bosco, MD, Jun 27, 2013. [See original video in Spanish].

Thessaloniki ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Consensus on infertility treatment related to polycystic ovary syndrome. Hum Reprod 2008; 23(3):462-77

Zawadski JK, Dunaif A. Diagnostic criteria for polycystic ovary syndrome: towards a rational approach. En: Dunaif A, Givens JR, Haseltine FP, Merriam GR (eds.). Polycystic ovary syndrome. Boston: Blackwell Scientific Publications. 1992:377-384.

FAQs from users: 'What are my chances of getting pregnant with IUI if I have PCOS?', 'Can PCOS be cured?', 'Can metformin help you get pregnant with PCOS?', 'Does PCOS run in the family?' and 'What treatment options can help you get pregnant with PCOS?'.

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Authors and contributors

 Carmen Ochoa Marieta
Carmen Ochoa Marieta
M.D., Ph.D., M.Sc.
Bachelor's Degree in Medicine from the Basque Country University. PhD in Medicine & Surgery from the University of Murcia. Currently, she is the director of the Assisted Reproduction Unit of Centro de Estudios para la Reproducción (CER SANTANDER) in Santander, Spain, as well as the director of the Diagnostic Unit of Human Assisted Reproduction in Bilbao. More information about Carmen Ochoa Marieta
License: 484805626
 Miguel Ángel Vincenti Bosco
Miguel Ángel Vincenti Bosco
Bachelor's Degree in Medicine, with specialization in Gynecology & Obstetrics. Expert in Reproductive Medicine, with extensive experience as Medical Director of fertility clinics. Currently, he works as an specialist in the field at Instituto de Reproducción Asistida Quirónsalud Dexeus Murcia and the Assisted Reproduction Unit of Hospital Quirónsalud Torrevieja. More information about Miguel Ángel Vincenti Bosco
 Rebeca Reus
Rebeca Reus
BSc, MSc
Degree in Human Biology (Biochemistry) from the Pompeu Fabra University (UPF). Official Master's Degree in Clinical Analysis Laboratory from the UPF and Master’s Degree about the Theoretical Basis and Laboratory Procedures in Assisted Reproduction from the University of Valencia (UV). More information about Rebeca Reus
 Zaira Salvador
Zaira Salvador
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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