Anovulation or lack of ovulation is defined as the condition in which follicular development and rupture is impaired. It results in infertility as the oocyte is not released from its follicle. This ovarian dysfunction can be due to genetic disorders or hormone deficiency. Common causes of ovulatory disorders are PCOS, premature menopause, excess prolactin or low gonadotropic hormones. Excess loss of weight, extreme exercise, uses of certain drugs and stressful environment also can cause anovulation. Ovulation detection tests are direct tests such as ultrasound or laparoscopic visualisation of follicular rupture, and indirect tests such as progesterone dosage, basal temperature curve and endometrial biopsy. Ovulation can be predicted by serum estradiol and LH concentrations and evaluation of the cervical mucus.