MSFinals-3465

A 16-year-old female who is 23 weeks pregnant (G1PO) arrives at the emergency department complaining of severe lower abdominal pain. She has a history of multiple sexual partners and was recently treated for gonorrhoeae with ceftriaxone. Although she does not take any regular medications, she admits to using illicit drugs such as marijuana and cocaine. During the physical examination, you notice that her uterus is hard and tender. What risk factor in her medical history is likely to contribute to her diagnosis?