Prolactin is a hormone produced by the pituitary gland in your brain that is responsible for milk production. Normally, prolactin levels rise significantly during pregnancy. As a result, the mammary glands get bigger and develop glandular lobules which will produce milk after childbirth.
A high level of prolactin in non-pregnant women can be accompanied by anovulation, missed periods, and conception difficulties. Possible causes of high prolactin levels include thyroid gland abnormalities, stress, taking certain medications, or neoplasms in the pituitary gland. These conditions require additional examination and treatment by a gynecologist