Q: I recently had a pre-conception counseling session with my doctor. Everything
looked good, she prescriped prenatals and the usual (I'm thinking of getting
pregnant in the next year and I've never been pregnant before). Her nurse just
called me and said that the doctor wants to do a thrombophilia panel of tests
on me. I looked up a little bit about this test online and I'm wondering if
it's normal for a doctor to want to do those tests on a healthy individual
before that person gets pregnant? I don't have anything unusual in my history
that would make me think I'm at a risk for venous thrombosis. I've left a message
for the doctor but since it will probably be days before I hear back from her,
I thought maybe you would have some insight. Thanks for any advice you have.
Dr. Donnica: Well, you've stumped me! I can't think of why your doctor would
order this as a "screening test" unless there's something in your history
you haven't mentioned or perhaps she did screening clotting tests and the results
came back abnormal. It is true that genetic risk factors predispose certain individuals
to venous thrombosis and that pregnancy (and taking birth control pills) are also
increased risk factors for venous thrombosis even in women who are not genetically
predisposed. In general, thrombosis panels include tests for several genetic mutations:
the Factor V Leiden R506Q mutation, Prothrombin (Factor II) 20210 G-A mutation,
and the MTHFR 677 C-T variant.
The most common mutation associated with inherited thrombosis in American Caucasians
is the Factor V Leiden mutation. Genetic heterozygotes for the Factor V Leiden
mutation have an approximately 5 to 10-fold increased risk for venous thrombosis.
The second most common mutation associated with hereditary thrombosis is the
20210 G-A mutation in the prothrombin (Factor II) gene, which is associated
with increased plasma prothrombin levels. Heterozygote carriers of the prothrombin
20210 G-A mutation have an estimated 3 to 8-fold increased risk for venous thrombosis.
In addition, compound heterozygosity for both the Factor V Leiden and the prothrombin
20210 G-A mutations tends toward earlier onset of thrombosis and greater severity
compared to the presence of either mutation alone in the heterozygous state.
In general, physicians refer patients for these tests in order to evaluate:
- Patients with venous thrombosis
- Cases of venous thrombosis in pregnant women or women taking oral contraceptives
- Female smokers with myocardial infarction under age 50
- Asymptomatic individuals with a family history of venous thrombosis
- Individuals with relatives known to have a thrombophilia risk factor mutation
- Women with recurrent pregnancy loss, unexplained severe preeclampsia, intrauterine
fetal growth retardation, or stillbirth
Created: 4/8/2005  - Donnica Moore, M.D.
All the content contained herein is copyrighted pursuant to federal law. Duplication or use without
the express written permission of DrDonnica.com subjects the violator to both civil & criminal penalties.
Copyright © 2006 DrDonnica.com. All rights reserved.
| Today on DrDonnica.com
| Meet Dr. Donnica
| TV Appearances
| Clinical Trials
Diseases & Conditions
| Celebrity Speak Out
| Guest Experts
| Women's Health Champions
| Women’s Health Resources
| Books & Tapes
| Site Certification
| Advanced Search
| What’s New?
| Press Room
| Contact Us