Polycystic ovarian syndrome (PCOS)

PCOS is a commonly diagnosed condition in reproductive aged women that can affect fertility. The cause of PCOS is complex and despite decades of research, it remains poorly understood,

Diagnosis of PCOS

PCOS is often diagnosed after a woman presents with a complaint of infertility. To be diagnosed with PCOS, two of the three following criteria must be met:

  • Infrequent menstrual cycles
  • Clinical signs of high androgen levels (unwanted hair growth, acne) or tests that show high androgen levels in the blood
  • Polycystic ovaries on ultrasound 

Polycystic ovaries on ultrasound

The term “polycystic” ovaries can be misleading and sound worrisome to patients or health care providers who are not familiar with the ovaries. The “cysts” in this case are actually small ovarian antral follicles that contain eggs, and should not be confused with larger cysts that can be of medical concern. Most women are born with these antral follicles and select one dominant follicle each month, which is then ovulated or released in anticipation of pregnancy. In women with PCOS, there is an excess amount of these small follicles, and the selection of one dominant follicle does not happen every month or sometimes does not happen at all. This is referred to as oligo-ovulation or anovulation, and leads to infrequent menstrual periods.

Historically, having 12 or more small follicles per ovary in either ovary was consistent with “polycystic” ovaries. Because most young reproductive-aged women typically have 12 or more small follicles per ovary, this threshold has led to over-diagnosis of PCOS. To combat these problem, the Androgen Excess and Polycystic Ovary Syndrome Society recently advocated increasing the threshold of defining polycystic ovaries on ultrasound from 12 follicles to 25 follicles.1

PCOS & Infertility

The main source of infertility in women with PCOS is the infrequent ovulation described above. However even in women with PCOS who ovulate regularly, changes in the lining of the uterus can discourage implantation. In PCOS women who do not ovulate regularly, ovulation can be induced with oral medications such as clomiphene citrate or letrozole, and should ideally be done under the supervision of a gynecologist or reproductive endocrinology & infertility specialist.

PCOS & Pregnancy

After conceiving, women with PCOS are at risk of developing certain pregnancy complications such as gestational diabetes, preterm delivery and pre-eclampsia, and this can be exacerbated by obesity. The Endocrine Society recommends assessment of BMI, blood pressure and oral glucose tolerance prior to attempts at conceiving.2

PCOS & Other Medical Conditions

Women with PCOS are also at risk of developing Type 2 diabetes, metabolic syndrome, endometrial cancer, cardiovascular disease and depression.2These women should be screened accordingly for these conditions. Weight loss in obese women with PCOS can reduce some of the risks, and can be accomplished with lifestyle modification such as exercise and diet intervention as a first line therapy. In women who are not trying to conceive, hormonal contraceptives are recommended to manage the menstrual cycle so as to decrease the risk of endometrial cancer. Hormonal contraceptives are also useful in women with unwanted hair growth and acne, who are not trying to conceive.

At Laurel Fertility Care, skilled reproductive endocrinologists are available to help patients with PCOS who are having difficulty conceiving. If you are interested in learning more, please contact us to arrange an appointment.


  1. Definition and significance of polycystic ovarian morphology: a task force report from the Androgen Excess and Polycystic Ovary Syndrome Society. Human Reproduction Update 2014; 20 (3): p334-352
  2. Diagnosis and treatment of polycystic ovary syndrome: an endocrine society clinical practice guideline. J Clin Endocrinol Metab, 2013; 98(12):4565-4592