Q. A 29-year-old woman with a known diagnosis of polycystic ovarian syndrome (PCOS) and a history of infertility presents to her primary care physician with a positive home pregnancy test. She reports her menstrual cycle has become more regular over the past few months. She has been trying to conceive for the past three years without success. Her medical history is significant for diabetes mellitus type 2, diagnosed two years ago, and she is currently on oral medication. Her body mass index (BMI) is 32 kg/m^2. She does not use tobacco, alcohol, or illicit drugs. On physical examination, she is vitally stable with unremarkable systemic examination. What medication is most likely to have contributed to her achieving pregnancy?