How Does PCOS Affect Female Fertility?

By BSc, MSc (embryologist), BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 01/12/2015

Polycystic Ovary Syndrome (PCOS) is an endocrine disorder that affects the female reproductive tract by causing abnormalities in sex hormone levels.

For this reason, about 75 percent of women with PCOS have infertility problems and find trouble when attempting to get pregnant.

The main symptom of this endocrine cause of female infertility is anovulation, that is, when the ovaries are unable to release an oocyte during the menstrual cycle.

The different sections of this article have been assembled into the following table of contents.

PCOS & infertility

PCOS is the most common endocrine disorder in women of childbearing age. It is diagnosed in about 5-10% of women after seeing multiple antral follicles with a common pattern through ultrasound scan.

Nonetheless, a hormone analysis is the only test that is actually able to render a conclusive diagnosis of PCOS, since this disorder causes abnormalities in sex hormone levels.

The following are the main signs and symptoms of PCOS, which are linked to infertility issues in females.


In PCOS patients, menstrual irregularities (including abnormalities during menstruation or amenorrhea), are an indicator of anovulation (absent ovulation).

Chronic anovulation is the main clinical sign of Polycystic Ovary Syndrome (PCOS).

The reason why the woman lacks ovulation is an imbalance in FSH and LH levels, the hormones that are in charge or regulating the menstrual cycle. Specifically, increased FSH levels trigger follicle development. Then, the LH surge causes the egg to be released during the ovulation phase of the cycle.

Abnormalities in FSH and LH levels are associated with the following abnormalities as well:

Since stimulation of FSH production does not occur, androgens do not become estrogens due to the action of aromatase enzyme. As a result, the levels of male hormones in blood are too elevated, causing side effects such as hirsutism.
Insulin resistance
High insulin concentrations in blood contribute to increasing the levels of androgens, and therefore to aggravate the situation of anovulation.

Finally, diminished FSH levels, and the subsequent lack of estrogens, causes the follicles to become atretic, forming cysts in the ovaries.

If you liked this section, you may want to go through this: What Is Anovulation?

Endometrial receptivity

In addition to ovulation and fertilization to create a new embryo, endometrial quality is crucial for embryo implantation and development to occur.

The endometrial lining (endometrium) renews and becomes receptive monthly thanks to the effect of estrogens and progesterone, both produced by the ovaries.

As already explained, the synthesis of estrogens and progesterone is altered is women with PCOS.

As a consequence of these abnormalities, endometrial receptivity is significantly lower in PCOS patients, and hence the chances for the embryo to attach to the uterus, causing implantation failure.

Risks of undergoing fertility treatment

Due to the number of infertility problems caused by PCOS, many women decide to undergo ovarian stimulation with ovulation induction to be able to get pregnant.

Although these treatment options are recommended by reproductive endocrinologists, they are not risk-free due to an elevated amount of follicles in the ovaries. The following are the main side effects:

Ovarian hyperstimulation syndrome

Ovarian Hyperstimulation Syndrome (OHSS) is an excessive response of the ovaries to ovarian stimulation drugs.

Since women with PCOS have an exaggerated number of antral follicles, the risk of developing OHSS is higher for them.

Thus, reproductive endocrinologists should monitor the ovarian stimulation cycle more closely in these patients by means of ultrasound scan as well as measuring estradiol levels in blood.

In the most severe cases of OHSS, the patient has symptoms of ascites (pathologic fluid collection within the abdomen), a rapid weight gain, tachycardia, and breathing difficulty.

More on this story: What Is the Ovarian Hyperstimulation Syndrome (OHSS)?

Multiple pregnancy

The risk of getting pregnant with multiples is a key aspect to consider when a couple undergoes timed intercourse or IUI (intrauterine insemination) and there exist more than 2 or 3 mature follicles in the ovaries.

For this reason, very low doses of hormone medications should be prescribed. If, in spite of this, more follicles than desired develop, the cycle will have to be cancelled, and the patient must have protected sexual intercourse.

The following are the main complications of multiple pregnancies:

  • Increased risk of preterm birth
  • Twin-to-twin transfusion syndrome (TTTS)
  • Low birth weight
  • Increased likelihood of placental complications
  • Increased maternal weight during pregnancy
  • Gestational diabetes and preeclampsia

Related content: Multiple Pregnancy Risks.

Considering seeing a fertility specialist? Don't forget that, in the field of Reproductive Medicine, as in any other medical area, it is crucial that patients rely on the doctors and staff that will help them through their treatment cycle. Logically, conditions vary from clinic to clinic. For this reason, we recommend that you generate your Fertility Report now. It will offer you a list of clinics that have passed our rigorous selection process successfully. Furthermore, the system will make a comparison between the fees and conditions of each clinic so that you can make a better-informed decision.

FAQs from users

Why are AMH levels so high in women with PCOS?

By Zaira Salvador BSc, MSc (embryologist).

Anti-Müllerian hormone (AMH) is produced by pre-antral and antral follicles present in the ovaries. For this reason, PCOS patients usually have too elevated AMH levels (about 6 ng/ml approximately).

What are the risks I should expect during pregnancy if I have PCOS?

By Zaira Salvador BSc, MSc (embryologist).

Some studies have shown that women with PCOS have a greater risk of miscarrying. Moreover, there are other obstetric complications to keep in mind, including:

  • Gestational diabetes
  • Preeclampsia
  • Low birth weight
  • Preterm birth
  • C-section

For these reasons, women with PCOS are more likely to go through a high-risk pregnancy.

I have PCOS but my body mass index is normal, should I lose weight to improve my insulin levels?

By Victoria Moliner BSc, MSc (embryologist).

Diet and physical exercise to lose weight are general recommendations in cases of PCOS where, additionally, the woman is overweight. If you are already on your weight, you do not need to start a weight loss diet plan. In fact, losing weight can even worsen the situation.

What additional metabolic disorders are associated with PCOS?

By Zaira Salvador BSc, MSc (embryologist).

Aside from the ones already listed, hyperinsulinemia associated with PCOS leads to the development of other long-term metabolic disorders, such as:

  • Diabetes type II
  • Cardiovascular risks
  • Obesity, increased triglyceride, total cholesterol and LDL levels
  • Endometrial hyperplasia and gynecological cancer

I have PCOS and I am about to undergo IVF, what are my chances of getting pregnant with multiples?

By Victoria Moliner BSc, MSc (embryologist).

In this case, the chances of having a multiple pregnancy do not rise due to PCOS, since it depends on the number of embryos transferred.

If a woman with PCOS undergoes a different treatment, namely timed intercourse or intrauterine insemination, the risk of multiple pregnancy would increase, though. In these cases, it is not possible to monitor the exact number of eggs released.

Why does a woman with PCOS have an increased risk of having gestational diabetes than a healthy woman?

By Victoria Moliner BSc, MSc (embryologist).

A pregnancy is a natural physiological state that generates insulin resistance. Insulin, due to the many changes induced by the pregnancy, becomes less effective and the organism needs to produce it in higher amounts for glucose to be effectively absorbed.

On the other hand, insulin resistance is a common symptom of PCOS. So, if both situations occur simultaneously (pregnancy and PCOS), the chances for the woman to develop gestational diabetes or type II diabetes in the future increase.

Suggested for you

If you are trying to conceive but you suffer from PCOS, we strongly recommend that you have a look at this post: What Are a Woman’s Chances of Conceiving with PCOS?

Also, if you need further information on the possible treatment options of PCOS, continue reading here: What Are the Different Treatment Options for PCOS?

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


Anttila L, Karjala K, Panttila RA, et al. PCOS in women with gestational diabetes. Obstet Gynecol 1998; 92: 13-16.

Balen AH, Conway GS, Homborg R, Legro RS. PCOS – A Guide to Clinical Management. London: Taylor & Francis 2005.

Balen, A.H., Dresner, M., Scott, E.M., Drife, J.O. (2006). Should obese women with polycystic ovary syndrome receive treatment for infertility? BMJ, 332, 434-435.

Diamanti-Kandarakis, E. (2006). Insulin resistance in PCOS. Endocrine, 30(1), 13-17.

Dunaif A. Insulin resistance and the polycystic ovary syndrome: mechanism and implications for pathogenesis. Endocr Rev 1997; 18(6): 774.

Franks S. Polycystic ovary syndrome. N Eng J Med 1995; 333: 853-86.

Golan A, Ron-El R, Herman A, Sofer Y. Ovarian hyperstimulaion syndrome: an update dreview. Obstet Gynecol Surv 1989; 44: 430-40.

Kiddy DS, Hamilton Fairley D, Bush A, et al. Improvement in endocrine and ovarian function during dietary treatment of obese women with PCOS. Clin Endocriol 1992; 36: 105-11.

Portsky L. On the paradox of insulin induced hyperandrogenism in insulin resistant states. Endocr Rev 1991; 12: 3-13.

Schenker JG, Ezra Y. Complications of assisted reproduction techniques. Fertil Steril 1994; 61: 411-22.

Urman B, Sarac E, Dagan L, et al. Pregnancy in infertile PCOD patients, complications and outcome. J Reprod Med 1997; 42: 501-5

FAQs from users: 'Why are AMH levels so high in women with PCOS?', 'What are the risks I should expect during pregnancy if I have PCOS?', 'I have PCOS but my body mass index is normal, should I lose weight to improve my insulin levels?', 'What additional metabolic disorders are associated with PCOS?', 'I have PCOS and I am about to undergo IVF, what are my chances of getting pregnant with multiples?' and 'Why does a woman with PCOS have an increased risk of having gestational diabetes than a healthy woman?'.

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Authors and contributors

 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
 Zaira Salvador
Zaira Salvador
BSc, MSc
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
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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