Although blood loss during modern dilation and evacuation procedures is well tolerated by most patients, one of the most common complications is heavy bleeding if the uterus doesn’t contract appropriately after the procedure.  As physicians, we prevent and treat heavy bleeding with a range of different “uterotonic” medications given in a wide variety of different manners. Although we know a lot about how these medications work in pregnant women who are full term, we don’t know if they work as well in the uterus of a woman in the second trimester of pregnancy. This problem is especially important in outpatient abortion clinics where many clinicians give medications routinely to prevent heavy bleeding.  Patients are exposed to medications that may not be effective and have to deal with associated side effects. From a resource perspective, this results in a higher incidence of uterotonic agent usage and prolonged periods of observation, leading to higher cost for a procedure that is usually paid out-of-pocket.
One of the biggest challenges in researching the effects of different uterotonics during dilation and evacuation procedures is that we don’t have a way of measuring exactly how much blood a patient loses.  This is because blood is mixed with amniotic fluid throughout the entire procedure.  In our research we aimed to fix this problem by finding a way to measure blood loss during dilation and evacuation. 
We performed several experiments in the laboratory using donor blood and amniotic fluid.  We also asked doctors to take color-matching tests to determine if they could complete their portion of the protocol.  Finally, we tested the full blood loss measurement protocol with several patients in the operating room during actual procedures.  At a basic level, our protocol measures the concentration of blood in a patient’s veins and compares that to the concentration of the blood that she loses during the procedure.  This allows us to estimate how much amniotic fluid to subtract from the final blood loss total.  Results show that this protocol is a precise and accurate method of measuring blood loss during dilation and evacuation research that improves upon existing blood loss measurement strategies.