Which type of abnormal uterine bleeding is most common in women of reproductive age?

The most common type of abnormal uterine bleeding in women of reproductive age is anovulatory bleeding. This occurs when the menstrual cycle does not involve regular ovulation, leading to irregular levels of hormones like estrogen and progesterone. In women who are of reproductive age, fluctuations in hormone levels can lead to unpredictable bleeding patterns, which is characteristic of anovulatory cycles.

Anovulatory bleeding can be particularly prevalent during early adolescence and perimenopause when ovulatory patterns are inconsistent. In these stages, the body may still produce estrogen, causing a buildup of the endometrial lining without the subsequent decline in estrogen and the rise in progesterone that would normally occur after ovulation. As a result, when the lining sheds, it can do so irregularly, leading to heavy or prolonged bleeding.

In contrast, ovulatory dysfunction typically involves some form of ovulation followed by irregular bleeding rather than a complete lack of ovulation. Structural causes generally refer to physical abnormalities such as fibroids or polyps which can also cause bleeding but are less frequent than hormonal causes in this age group. Iatrogenic causes are related to medical interventions or treatments and, while they can be relevant, they do not account for the majority of abnormal bleeding cases seen in reproductive-aged women