Don't Be Too Quick to Diagnose Teens With PCOS.

TORONTO -- Physicians who are hasty to do a lab work-up on teenage girls with irregular periods may find themselves chasing a false diagnosis of polycystic ovary syndrome.

"The biggest thing we're asked to face as pediatric gynecologists is teenagers with dysfunctional uterine bleeding. But it's absolutely normal to have abnormal periods. We should not panic, and we should not overtreat," Dr. Jay Spence said at the annual meeting of the North American Society for Pediatric and Adolescent Gynecology.

Ovarian hyperandrogenism is a normal transient stage in teens that usually resolves within a few years of the start of menarche, said Dr. Spence, who is professor of ob.gyn. at the University of Ottawa.

Polycystic ovary syndrome (PC OS) is a diagnosis that should be made very reticently early on, he said.

Physicians who see teenagers with irregular periods should be aware that the first 2 years of menstrual periods are characterized by wide swings in the length of menstrual cycles. Studies have shown a range of around 18-83 days between periods in the first year of menarche, compared with a range of 19-42 days by the seventh year of menarche.

From 2 to 4 years after the first period the intervals should begin to normalize, and the periods should become more predictable and less heavy, he said in an interview.

Dr. Spence strongly advises against drawing blood early in the investigation because early postmenarchal endocrine patterns look misleadingly like PCOS; they include elevated testosterone, androstenedione, dehydroepiandrosterone, and luteinizing hormone, as well as decreased sex hormone-binding globulin.