<prompt> MC cause of anovulation is-PCOSHyperprolactinemiaPremature ovarian failureLow ovarian reserves  <response>: Ans. is a i.e., PCOS Anovulation and ovulatory dysfunction can be caused by a number of factors. The most common cause of ovulatory dysfunction is polycystic ovarian syndrome, or PCOS. Other potential causes of irregular or absent ovulation: Obesity Underweight Extreme exercise Hyperprolactinemia Premature ovarian failure Perimenopause, or low ovarian reserves Thyroid dysfunction Extremely high levels of stress 