Call during UWHC rotations (Student Health, REI, Gyn Onc, and Gynecology) is home call, and on average is every 4th night. PGY-1's - PGY-4's participate in home call. There is a night float system in place for the Meriter obstetric and gynecology and St. Mary's obstetric services. In-house call during these rotations is 1 in 7. During the Ultrasound (PGY-1) rotation, there is obstetric call of 1 in 7. There is no call during the Elective rotation.