Uterine bleeding can be normal or abnormal. Normal uterine bleeding refers to menstruation, which does not lead to infertility. Lack of uterine bleeding may indicate abnormal endocrine function, which could potentially cause infertility. However, if uterine bleeding occurs at times other than menstruation, it is considered abnormal uterine bleeding. There are various causes for abnormal uterine bleeding, and it can affect pregnancy. The most common reason for abnormal uterine bleeding is hormonal imbalance, which leads to irregular ovulation and may result in infertility.