Thrombophilia Screening Before Combined Oral Contraceptives in Adolescents
Routine thrombophilia screening is NOT recommended before prescribing combined oral contraceptives to adolescents; screening should be limited to those with a first-degree family history of venous thromboembolism before age 60. 1
When to Screen: The Specific Criteria
Screen only if:
- First-degree relative (parent or sibling) had a venous thromboembolic event before age 60 1
Do NOT screen if:
- No family history of thrombosis
- Family history of superficial venous thrombosis only (this does NOT contraindicate hormonal contraception) 1
- General "low-risk" population screening 2, 3, 4
What Tests to Order When Screening IS Indicated
When a positive family history warrants screening, order the following panel 1:
- Prothrombin time (PT)
- Activated partial thromboplastin time (aPTT)
- Antithrombin level
- Protein C level
- Protein S level
- Factor V Leiden mutation
- Prothrombin (Factor II) G20210A mutation
The Evidence Behind This Approach
The French Society of Endocrinology guidelines from 2012 explicitly state: "there is no need for routine screening for thrombophilia when prescribing a hormonal contraceptive; these investigations should be limited to women with a first-degree family history before age 60" 1. This represents the most recent and specific guideline addressing this clinical scenario.
The rationale is straightforward: universal screening is not cost-effective 4, 5. While combined hormonal contraceptives do increase VTE risk (particularly in the first year of use), and this risk is amplified 5-16 fold in women with inherited thrombophilia 1, the absolute risk remains low in the general adolescent population. The prevalence of thrombophilia is insufficient to justify screening costs and potential harms (including insurance discrimination and psychological burden) 6 in unselected populations.
Clinical Context: Why Age 60 Matters
The age cutoff of 60 years for family history is clinically meaningful. Thrombotic events occurring before age 60 in first-degree relatives suggest a stronger hereditary component and higher likelihood of clinically significant thrombophilia 2. Events after age 60 are more likely related to acquired risk factors (malignancy, immobility, surgery) rather than inherited thrombophilia.
What If Screening Reveals Thrombophilia?
If documented biological thrombophilia is found:
- Combined estrogen-progestin contraception is formally contraindicated 1
- Safe alternatives include:
- Copper IUD
- Levonorgestrel IUD
- Progestin-only pills (microdose or macrodose)
- Subcutaneous implants
- Avoid depot medroxyprogesterone acetate (DMPA) - this is also contraindicated 4
Important Caveats
Targeted screening may be considered in specific high-risk scenarios beyond the age 60 cutoff 2:
- Adolescent with personal history of VTE (though this already contraindicates combined contraceptives)
- Known family member with documented Factor V Leiden or prothrombin mutation, where knowledge may influence contraceptive decision-making 2
- Myocardial infarction in young female smokers under age 50 2
Common pitfall to avoid: Do not confuse family history of arterial events (stroke, MI) with venous thrombosis. The screening recommendations apply specifically to venous thromboembolic disease 2. Arterial events require different risk assessment.
The Adolescent-Specific Consideration
While most guidelines don't specifically differentiate adolescents from adults, the principles apply equally. Adolescents account for 5-10% of all contraception-related VTE events despite low absolute risk 7. Most adolescents who experience contraception-related VTE have additional risk factors present 7, reinforcing the importance of targeted rather than universal screening.
Bottom line: Take a focused family history asking specifically about blood clots in legs or lungs in parents or siblings before age 60. If negative, proceed with contraceptive counseling without thrombophilia testing. If positive, order the complete panel listed above before prescribing combined hormonal contraceptives.