The development of blood clots (DVT) postoperatively is one of the greatest concerns surgeons have for patients in the postoperative period. A blood clot can cause problems in the vicinity of the clot but can also break off and travel to the lungs resulting in a potentially lethal outcome. For that reason most surgeons utilize a screening system preoperatively that assigns a numerical grade to each of several known risks related to the development of a blood clot. One of the most important risk factors is the use of birth control pills. Typically surgeons will recommend that these be discontinued for 2 weeks before surgery and 2 weeks postoperatively. If for some reason it is not possible to discontinue this type of medication it will likely be necessary to utilize some type of blood thinning agent postoperatively. Most surgeons however would prefer to eliminate a potential threat such as this by discontinuing it preoperatively.