Visualize at least 30 follicles: ultrasound criteria for PCOS said to be too loose

Visualize at least 30 follicles: ultrasound criteria for PCOS said to be too loose
by Kate Johnson
August 1, 2004

MONTREAL — The ultrasound diagnosis of a polycystic ovary should require the visualization of 30 follicles, not 12 as recently suggested in an international consensus statement on the subject, Dr. Donna Chizen said at the 18th World Congress on Fertility and Sterility.

“Women who have less than 30 follicles and particularly less than 20 follicles may well be absolutely normal in every way in terms of biochemical indices and menstrual histories. So if we came up with a definition that was more stringent it would be more helpful for diagnosing” polycystic ovarian syndrome (PCOS), Dr. Chizen said at the meeting, sponsored by the International Federation of Fertility Societies.

Experts at an American Society for Reproductive Medicine/European Society of Human Reproduction and Embryology consensus meeting last year released the “Ultrasound assessment of the polycystic ovary: international consensus definitions” (Hum. Reprod. Update, 9[6]:505-14, 2003).

According to that document, the ultrasound criteria to define PCOS “should have at least one of the following: either 12 or more follicles measuring 2-9 mm in diameter, or increased ovarian volume (>10 [cm.sup.3]).”

But the findings of her pilot study of 14 women with PCOS challenged this definition, Dr. Chizen of the University of Saskatchewan in Saskatoon said during the meeting.

“I undertook the study because in my experience, most women’s ovaries could be called PCOS if they were evaluated according to these new criteria,” she said.

She added that recent work by her colleagues shows that women who ovulate typically have 15-20 follicles in each ovary at different phases of the menstrual cycle (Biol. Reprod. 69[3]:1023-31, 2003).

Her study found that the international criteria for PCOS (12 follicles, each of which is 2-9 mm in diameter) were satisfied by counting follicles in just a single mid-sagittal or mid-transverse plane of the ovary in 42% of the women with PCOS. “If I looked at a total ovarian follicle count, I could easily see around 40 follicles in each ovary in most of these individuals” with PCOS, Dr. Chizen said in an interview.

The range of the total follicle count in both ovaries was between 25 and 66 follicles (mean 40 follicles).

“If you send someone for a routine ultrasound to diagnose the reason for infertility and you can count at least 30 follicles, then it’s pretty likely that they have PCOS,” she said.


Montreal Bureau

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