Nexplanon Use in Patients with Family History of Factor V Leiden
A family history of factor V Leiden alone does not contraindicate Nexplanon use, as progestin-only contraceptives like Nexplanon do not carry the same thrombotic risk as combined estrogen-containing oral contraceptives. However, testing for factor V Leiden should be considered in this patient before prescribing any hormonal contraception, and if positive, Nexplanon remains a safer alternative to combined hormonal methods.
Key Distinction: Progestin-Only vs. Combined Hormonal Contraception
Progestin-only contraceptives (including Nexplanon/etonogestrel implant) do not increase venous thromboembolism (VTE) risk in the same manner as combined oral contraceptives containing estrogen 1.
The 30-fold increased VTE risk discussed in guidelines specifically applies to combined oral contraceptives (estrogen + progestin) in factor V Leiden heterozygotes, not progestin-only methods 1.
Combined oral contraceptives alone increase thrombosis risk 4-fold, which escalates to 30-fold in factor V Leiden heterozygotes, but this interaction is primarily driven by the estrogen component 1.
Testing Recommendations for This Patient
The American College of Medical Genetics recommends factor V Leiden testing for women with a family history of thromboembolism, APC resistance, or documented factor V Leiden mutation who are contemplating hormonal contraception 1.
Women with a family history of thromboembolism should be counseled about their risks and options and considered for testing, depending on the overall clinical situation 1.
Testing is particularly recommended for relatives of individuals with venous thrombosis under age 50 2.
The absolute annual VTE risk in heterozygous factor V Leiden carriers is modest (0.19-0.56% per year), but increases with age and additional risk factors 2, 3.
Clinical Decision-Making Algorithm
If Testing is NOT Performed:
- Nexplanon can be prescribed safely as it does not carry the estrogen-related thrombotic risk 1.
- Avoid combined hormonal contraceptives (pills, patches, rings) given the family history 1.
If Testing Shows Factor V Leiden Positive:
- Nexplanon remains an appropriate choice as progestin-only methods are not contraindicated in thrombophilia 1.
- Absolutely avoid combined hormonal contraceptives, which would increase VTE risk to nearly 50-fold in carriers 4.
- Counsel the patient about VTE risk in other high-risk situations (surgery, prolonged immobility, pregnancy/postpartum) 1.
If Testing Shows No Factor V Leiden:
- Nexplanon is safe 1.
- Combined hormonal contraceptives could be considered, though family history still warrants caution and consideration of other inherited thrombophilias 1.
Important Clinical Caveats
Family history alone has poor predictive value for detecting factor V Leiden carriers (positive predictive value only 12-14%), so a negative family history does not rule out the mutation 5.
The American College of Medical Genetics explicitly states that routine screening of all asymptomatic women is not recommended due to cost-effectiveness concerns and potential psychosocial harms (insurance discrimination, job-related issues) 1, 2.
If the patient has a personal history of VTE (not just family history), this would be a contraindication to all hormonal contraception including Nexplanon, and testing becomes mandatory 1.
In pregnancy contexts, heterozygous factor V Leiden carriers with family history of VTE have low absolute antepartum risk (0.50%), but this does not directly translate to contraceptive decision-making 1.
Practical Recommendation
Prescribe Nexplanon without hesitation in this patient, as progestin-only contraception does not share the thrombotic risk profile of combined hormonal methods. Consider offering factor V Leiden testing to inform future contraceptive choices and counsel about VTE risk in other clinical scenarios, but testing is not mandatory before Nexplanon initiation 1, 2.