[Rotterdam consensus in adolescent girls: which investigations and how to interpret them to make the diagnosis of PCOS?].

The polycystic ovary syndrome (PCOS) is the most frequent cause of hyperandrogenism and anovulation in adult women as well as in adolescent girls. Since 2003 the diagnosis of PCOS has been based on the association of hyperandrogenism, oligoanovulation and polycystic ovary (PCO) morphology at ultrasound (at least 2 items out of 3). In adolescents however, PCOS features may be difficult to distinguish from the symptoms of the end of puberty. Moreover, transvaginal ultrasound examination is seldom possible, and it is difficult to get precise imaging of the ovaries by abdominal route. However, the diagnosis of PCOS in a hyperandrogenic and/or oligomenorrheic adolescent requires on the strict application of the Rotterdam criteria, as in adult women. Priority should be given to clinical features whereas pelvic ultrasound must be considered as optional. Few hormonal assays will serve mainly to make the differential diagnosis, in addition to clinical findings. Once established, the diagnosis of PCOS in an adolescent girl must lead to the detection of the metabolic syndrome by means of simple investigations. This will allow early prevention of its complications.