A 19 year old sexually active female presents to urgent care with abdominal pain and nausea. Her last menstrual period began seven days ago. Physical examination is remarkable for fever and lower abdominal pain. Pelvic examination reveals a mucopurulent discharge, adnexal tenderness, and tenderness with cervical motion. A pregnancy test is negative; the patient's white count is elevated. Which of the following complications is associated with this disorder?