The medical device has a shield and an arm secured to the shield at one end and extending outwardly from the shield. The arm is inserted into the cervical canal of a patient and the shield covers the external os of the patient. By inserting the medical device into a patient's cervical canal prior to insemination and leaving the device in place after insemination, a physical barrier that holds a semen sample within the cervical canal and prevents leakage from the cervical canal back into the vaginal cavity is established. The device may have a bore extending through the device for a catheter to pass through. The bore has a valve to allow passage of the catheter and prevent backflow of semen. The arm may have a plurality of longitudinal ridges, circumferential ridges, or circumferential barbs to help keep the device in place.