What is the key feature of polycystic ovary syndrome (PCOS)?

The key feature of polycystic ovary syndrome (PCOS) is that it is primarily characterized by oligo-ovulation or anovulation. This condition often leads to irregular menstruation due to hormonal imbalances that disrupt the normal ovulation cycle. Women with PCOS frequently experience infrequent or absent ovulatory cycles, which is a fundamental aspect of the disorder.

While irregular menstrual cycles, excessive hair growth, and infertility are common associated symptoms of PCOS, they stem from the underlying issue of anovulation. The hormonal imbalance in PCOS primarily affects the ovulatory process, which can result in a variety of symptoms, including the other options listed. However, the defining characteristic that classifies PCOS as a syndrome is the presence of oligo-ovulation or anovulation. This makes it vital to assess ovulatory function when considering the diagnosis and management of PCOS.