Question From the Clinician: Risk of Thrombophilia
Bibliographic record
Abstract
A 17-year-old girl meets with you to discuss her use of oral contraceptives (OCPs) that contain estrogen. In the family history focusing on evidence of thrombophilia, you find that the patient’s father died of a pulmonary embolus after disembarking from a transatlantic airplane flight. The patient and her mother want to know if she should use OCPs. The girl is leaving for college, and there is concern for an unwanted pregnancy on the one hand and the risk of thrombosis on the other. How should you advise her?In this case, the family history provides a vital piece of information in assessing risk of thrombosis for this patient using OCPs. The current guidelines of the American College of Obstetrics and Gynecology do not recommend laboratory testing for thrombophilia if a careful family history is unrevealing. (1) In view of the father’s pulmonary embolus and demise, a consideration of inherited abnormalities that may predispose to a thrombus and acquired conditions that may provoke a thrombus is warranted. The father’s long airplane ride, particularly if it was in the coach section with limited mobility, is a risk factor for a lower extremity or pelvic thrombus and consequent pulmonary embolus, although at least one-third to one-half of the adult patients who experience pulmonary emboli do not have an identifiable source of the embolization. (2) The thrombotic risk would be heightened if he had an underlying malignancy or inflammatory disease, but there was no history of either of these conditions.If the immobilization of the airplane ride were coupled with an inherited thrombophilic condition, such as factor V Leiden (5% of the population), the risk would be more than additive. In the scenario presented, we have no information about an underlying thrombophilic mutation; but the population frequency of such abnormalities makes it reasonable to explore this possibility in this young woman in view of her positive family history, because such a mutation would increase her risk of a thrombus if she used OCPs.An established thrombophilia panel includes genetic and plasma-based testing, (3)(4)(5) as follows:The results of plasma-derived coagulation tests performed in children should be compared with their respective age-appropriate values. (6) Furthermore, each thrombophilic factor noted presents a different risk for the development of a thrombus. (7)The routine testing of children for both acquired and inherited conditions is controversial, given the low prevalence of thrombotic events, the even lower prevalence of unprovoked events, and the variable presence of external risk factors (eg, limited mobility, central lines, estrogen-containing OCP medications). Thrombophilia testing to determine the duration of anticoagulation in children or to prevent venous thromboembolism or life-threatening events in adolescent patients being considered for oral contraception has not been recommended in the absence of a family or patient history of thrombosis. (8)(9)The patient in the case described should have a complete evaluation for a thrombophilic factor. If a risk factor is identified, estrogen-containing OCPs should not be used. If an abnormality is detected, it would be beneficial to take a multidisciplinary approach, involving a pediatric hematologist and a gynecologist, to consider the different contraceptive methods that are compatible with the results of the thrombophilia investigation. (10) Current data do not indicate any heightened risk of thrombosis with the use of progesterone alone as a contraceptive, and numerous barrier methods of contraception are available. Importantly, additional modifiable risk factors such as obesity, inappropriate diet and sedentarism, and exposure to alcohol and tobacco also need to be addressed.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.023 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.004 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.019 | 0.009 |
| Insufficient payload (model declined to judge) | 0.016 | 0.007 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".