What is the primary cause of anovulation leading to menstrual irregularities in polycystic ovarian syndrome?

In polycystic ovarian syndrome (PCOS), the primary cause of anovulation, which subsequently leads to menstrual irregularities, is the excess production of androgens. In women with PCOS, the ovaries often produce an increased amount of male hormones, such as testosterone, due to dysregulation in hormone signaling and ovarian function. This hormonal imbalance interferes with the normal ovulatory cycle, disrupting the regular release of eggs and leading to irregular or absent menstrual periods.

The presence of elevated androgen levels affects the ovarian follicles' ability to mature and release eggs, which is essential for regular ovulation. Consequently, women with PCOS frequently experience irregular menstrual cycles due to this anovulatory state, manifesting as oligomenorrhea (light or infrequent periods) or amenorrhea (absence of periods).

While insulin resistance and low estrogen levels can also play roles in the broader context of PCOS, and hyperprolactinemia may affect menstrual patterns, the root cause of anovulation specifically in this syndrome is primarily attributed to the excess androgens. Therefore, recognizing the impact of elevated androgen levels is crucial in understanding the menstrual irregularities associated with PCOS.