Friday, October 2, 2009
Women's Issues in Von Willbrands Disease
In the US menorrhagia occurs in 2-3 million individuals. As a result of that statistic almost 300,000 women undergo hysterectomy when in reality about 20% of these women have an underlying bleeding disorder. The most common disorder is VWD. Women having an undiagnosed coagulopathy results in the health crisis which is characterized by a poor quality of life, loss of work, unnecessary surgery, surgical morbidity, increased health care costs and psychological consequences. Even most publications for gynecologists exploring differential diagnosis of abnormal uterine bleeding may briefly mention, after all other measures have been exhausted, to investigate the possibility of a bleeding disorder. Gynecologists tend to focus on anatomical or hormonal problems and need to be made more aware of this disorder as well as do primary care physicians and internists.
Bleeding disorders in women
A major issue in the assessment of bleeding is the lack of a clinical tool for the objective measurement of abnormal reproductive tract bleeding. This added to the lack of awareness of the potential of bleeding disorders to increase or even cause abnormal bleeding leads to the under-diagnosis and suboptimal treatment of women with bleeding disorders. The prevalence of menorrhagia in women with VWD is 74-92% which increases with the severity of the type of VWD. A systematic review of 988 patients in 11 studies demonstrated 5-24% prevalence of menorrhagia is women with VWD, with an overall prevalence of 13%. A 1% prevalence in seen in the general population, but women are more likely to manifest the disorder due to bleeding from menstruation and childbirth. Menorrhagia is the most common symptom in women with VWD. Menorrhagia is defined as >80 mls of blood loss per menstrual cycle. In 2001 a common opinion issued by the American College of Obstetrics-Gynecologist Practice recommended to screen for bleeding disorders adolescents and adult women with severe menorrhagia before performing a hysterectomy.
In a case controlled study conducted by the CDC, more women with VWD had undergone a hysterectomy (28% versus 9%, p<0.01) at a younger age versus controls, but age was not statistically significant. Of 94 women who had undergone surgery, 61% had bleeding complications, with 46% requiring transfusions (p<0.01) as compared to 66 controls of which 8% required surgery and a transfusion. This study demonstrates the disproportionate incidence of bleeding in women with VWD and the expertise that is required by not only gynecologists to understand VWD but also by hematologists to understand anatomical issues with women.
The least amount of variation in VWF is 5-7 days of the cycle and has become the recommended time point for sampling for VWD studies. It was also noted the lowest level of VWF was in day 1-3 of cycle, samples taken at this time interval would represent the lowest value and be diagnostic value in treating women with DDAVP. VWF levels increase significantly in three situations:
1. supra-physiological dosing for ovarian stimulation in the setting of infertility
2. postmenopausal women deliberately taking high does of estrogens
3. pregnancy in a type 1 vWD patient.
Other confounding issues in VW testing are age and ABO blood type. VWF increases 15-17% per decade. It is not known if this increases until menopause. While in pregnancy, the third trimester brings an increase in VWF, >50%, which can cause a missed diagnosis. Pregnant women should have increased levels, therefore a normal level may mean an abnormal result.
In a study conducted on 123 randomly selected female control subjects ages 18-45, testing for VWD included ABO blood typing. Results revealed that women with blood Type O have significantly lower levels for all tests. When comparing levels for VWF:ag for blood types: normal range for VWF in all controls is 49-203 IU/dL, Type O patients 35.6-157.0 IU/dL, Type A 48.0-233.9 IU/dL, Type B 56.8-241.0 IU/dL, Type AB 63.8-238.2 IU/dL. ABO differences account for 19% of the variance in VWF:ag. This in turn has a large effect in determining ratios for diagnosing the different types of VWD. The ratio for VWF:Rco/VWF:ag were 0.97 in non-type O, versus 0.79 for type O and 0.94 and 0.74 for non-type O. Adding blood type into the mix of race and age only compounds the level of knowledge required when diagnosing women with this disorder.
One issue with implementing change is that women are tolerant of bleeding, it is a part of their lives and they do not seek medical help for this problem, additionally if they have daughters who are also "heavy bleeders" it then becomes transitional or passed on further exacerbating the issue. Women need to be educated and be made aware of this as well as the presence of other types of bleeding from VWD which include gastrointestinal bleeding, bleeding from dental or surgical procedures, epistaxis, petechiae, and purpura.
One of the most effective tools in demonstrating underlying coagulation abnormalities is a good clinical and family history. Utilizing a questionnaire that assesses type and severity of bleeding with a numerical value can provide clinicians with an objective tool. Women with three hemorrhagic symptoms or a bleeding score of five or more provides a 98.6% specificity in determining type 1 VWD. Having gynecologists use this scoring system may be an aid in referring patients to hematologists.
The National Heart, Lung and Blood Institute (NHBI) published their first evidence based guidelines "The Diagnosis, Evaluation, and Management of von Willebrand Disease" in March of 2008. This was aimed at not only hematologists and laboratory professionals, but for primary care physicians, gynecologists, pediatricians and nurse practitioners. A quick reference pocket guide provides a synopsis of these guidelines.
Educating women to become aware of this issue and take charge of pursing this diagnosis is one of the first steps to be taken. Many male gynecologists feel that women inherently complain and tend to ignore when they mention heavy bleeding. One venue to explore is to reach a younger generation of women through magazine ads by having them evaluate their own bleeding by tampon usage, quality of life and become aware of the possibility they have a bleeding disorder.
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