The very first step in evaluating the fertility of a patient is receiving a thorough medical history. The evaluating doctor will ask about previous evaluations, sexual habits, and how long the couple has been trying to achieve a pregnancy. They will also ask for a detailed sexual history, in order to determine that the patient understands about optimal intercourse timing, and that no sperm-toxic lubricants or drugs are used. Any previous infections, sexually transmitted diseases, and childhood illnesses should be disclosed, as they may be relevant to the diagnosis.