According to the Rotterdam criteria for PCOS, how many criteria must be met for diagnosis?

The Rotterdam criteria for the diagnosis of polycystic ovary syndrome (PCOS) stipulate that a patient must meet at least two out of three specific criteria to receive a diagnosis. These criteria include:

1. Oligo- or anovulation, which manifests as irregular menstrual cycles or the absence of ovulation.

2. Clinical and/or biochemical signs of hyperandrogenism, which can present as hirsutism, acne, or elevated levels of androgens.

3. Polycystic ovaries observed via ultrasound, defined by the presence of 12 or more follicles in at least one ovary or increased ovarian volume.

Thus, by fulfilling two of these three criteria, a diagnosis of PCOS can be established, making the requirement for meeting at least two criteria essential in the evaluation process. This approach also helps ensure that individuals are accurately diagnosed and that the syndrome is distinguished from other conditions that may present similarly.