I recently received the following question from an ASH member through the Society’s new Consult-a-Colleague program. He asked:
How would you counsel a patient who is an asymptomatic heterozygote with the Factor V Leiden mutation who is planning her first pregnancy and wants to take enoxaparin thromboprohylaxis? No other thrombophilic factor is identified, but her mother, who is also heterozygous for Factor V Leiden, had her first deep venous thrombosis (DVT) with her first pregnancy and has suffered from recurrent venous thrombosis ever since. The patient is adamant on taking the medication.
The Response
I agreed with his assessment that the absolute risk of such a patient developing a first DVT during an uncomplicated pregnancy is sufficiently low (<1 percent) to forego the need for ante-partum and even postpartum thromboprophylaxis. The thromboembolic event in her mother along with the severe sequelae, however, can drive patients to do all that is possible to minimize the risk of thrombosis. Thus, it is not unreasonable to defer to patient preference after thoroughly counseling her of the potential risks (e.g., bleeding, low risk of heparin-induced thrombocytopenia) and discomfort of low-molecular-weight heparin injections (as well as the cost of the medication) for many months along with the benefit (albeit small).
In working through the issues with the patient, it could be useful to try to get as much information as possible regarding the occurrence of the first episode of DVT in the mother—were there other risk factors that she had that are not present in the daughter? These might include older age at the time of the first pregnancy, obesity, or prolonged immobilization due to preeclampsia, or if the thrombotic event occurred in the post-partum state or following a C-section. If the doctor was able to identify such a risk factor, he might use this in bolstering the case that other risk factors contributed to the thrombotic complication in addition to Factor V Leiden. If he was able to ascertain such information, it might strengthen the argument that she is at substantially lower thrombotic risk than was her mother at the time of her first pregnancy. Finally, by counseling the patient regarding symptoms of venous thromboembolism requiring prompt medical evaluation, she would hopefully be promptly diagnosed if she developed venous thromboembolism and managed appropriately, lessening the possibility of long-term complications. It is also important that the patient’s obstetrician and hematologist are in agreement with respect to this issue so that clear and coherent information is communicated to the patient.
About the Consult-a-Colleague Program
The Consult-a-Colleague program was launched in June of this year to facilitate the exchange of clinically focused information with ASH colleagues. The program is being piloted in the areas of hemostasis/thrombosis and lymphoproliferative disorders. ASH members submit their questions through the ASH Web site. The questions are routed to one of seven consultants who are expected to respond directly to the submitter within one to two business days. I have received seven requests to date. The types of questions are similar to those posed to presenters at ASH Educational and Meet-the-Expert Sessions in hemostasis and thrombosis. The questions are practical and have all been directly related to the diagnosis and management of individual patients. A common theme has been the benefits and risks of anticoagulation in high-risk patients.
How to Consult a ColleagueVisit the Consult a Colleague page on the ASH Web site to take advantage of this member benefit. ASH is already looking toward expanding this program to cover other areas of hematology if it proves to be popular. User feedback is encouraged to help the leadership determine whether this is a valuable tool.