Polycystic Ovarian Syndrome: Updated Ultrasound Criteria

Polycystic ovarian syndrome or PCOS is a very common cause of chronic anovulation and infertility.  Unfortunately, there has been  recent confusion among health care providers as to which patients are most likely PCOS.  The confusion has come from studies that have included patients as PCOS based on ultrasound criteria.

The hallmarks of PCOS are oligomenorrhea (infrequent menstrual cycles due to infrequent ovulation) and hyperandrogenism (the presence of physical manifestations of increased male hormone levels).  Sometimes the history and physical signs can be vague.  For that reason, clinicians and researchers have been looking for more sensitive ultrasound findings.  Unfortunately, the bar for the PCOS criteria for ultrasound findings appears to have been set too low.  This has led to over diagnosing many patients as PCOS.

In my clinic, it is common to see a patient that has been told that she has PCOS based on ultrasound criteria only while she reports regular ovulatory cycles.  This is incorrect.  The findings of this study may lead to less incorrect diagnoses.  The authors report on a higher threshold of 26 or more resting follicles per ovary in patients that also have oligomenorrhea and hyperadrogenism.

The analysis showed that a threshold of 26 follicles struck the best compromise between sensitivity (85%) and specificity (94%) when discriminating between women with PCOS and control participants.

“Using newer ultrasound technology and a reliable grid system approach to count follicles, we concluded that a substantially higher threshold of follicle counts throughout the entire ovary (FNPO)—26 versus 12 follicles—is required to distinguish among women with PCOS and healthy women from the general population.”

Reference:  Hum. Reprod. (2013) 28 (5):1361-1368.doi: 10.1093/humrep/det062First published online: March 15, 2013

Julio E. Pabon, M.D., F.A.C.O.G.

copyright J. Pabon collection
copyright J. Pabon collection