Enlarged ovaries are common in healthy regularly menstruating adolescent girls and it appears to reflect a typically normal variation, clinicians from Illinois report in the Journal of Clinical Endocrinology and Metabolism. Nevertheless, about half of these girls have polycystic ovary syndrome (PCOS) type of ovarian dysfunction without symptoms, they note.

PCOS is a hormonal disorder involving enlarged ovaries with multiple cysts. Up to 10 percent of women have PCOS and it is a leading cause of infertility.

While recruiting healthy adolescent volunteers for studies of adolescent PCOS, Dr. Monica Mortensen and two colleagues from pediatric endocrinology at The University of Chicago noted a “high prevalence” of polycystic-size ovaries.

Among 22 teenage girls who had been menstruating for a few years, 12 had a polycystic-size ovaries and 10 had normal-size ovaries. Several of the girls with large ovaries had a hormone response similar to those of PCOS patients, but had no other features of the disease.

The authors conclude that the majority of teen girls who have a polycystic-sized ovary detected by chance are normal. However, about half have a PCOS-type of ovarian dysfunction. “It is unclear,” the authors note, “whether this represents a subgroup” that may be at risk for developing PCOS later.

SOURCE: Journal of Clinical Endocrinology and Metabolism, October 2006.