Prolactin is known as a gonadotrophic hormone, which means it affects the gonads or sexual organs. High prolactin levels affect the corpus luteum, which is the tiny secretory organ formed from the ruptured ovarian follicle after ovulation has taken place. This results in reduced progesterone function. Hyperprolactinaemia or high prolactin levels can be controlled in the majority of patients with medication alone. The most commonly prescribed drug for this purpose is bromocriptine, which works by inhibiting the release of prolactin from the pituitary gland. Many thousands of babies have been born to mothers taking bromocriptine and there is no evidence of any increased incidence of malformation or miscarriage.