Prolactin (PRL) is a hormone produced by the pituitary gland and its function is to stimulate the secretion of breast milk after birth. In addition, another function of prolactin is to stimulate the production of progesterone during the luteal phase of a woman's cycle.
Normal prolactin values in a non-pregnant woman should be between 0 and 20 ng/mL. When the concentration of prolactin in the body is altered, problems can occur in the menstrual cycle and cause anovulation.
An excess of prolactin blocks the production of GnRH and, as a consequence, also decreases the amount of FSH and LH hormone. Therefore, abnormal female prolactin levels may be a reason for female infertility.