Extend® Test: Double-Strand Sperm DNA Fragmentation Test for Fertility Insights
Helping Explain Miscarriage or Failed IVF: The Role of DNA Damage
Experiencing miscarriage or failed fertility treatment is heartbreaking and confusing. You deserve answers and hope. While many factors can contribute to pregnancy loss, research has shown that sperm quality, and specifically double-strand SDF damage (dsSDF), can be a contributing factor.
The Extend® test is the only commercially available test that exclusively measures double-strand sperm DNA breaks (dsDB), providing critical insights into male fertility. Whether you’re planning IVF, ICSI, or recovering from pregnancy loss, Extend® offers the clarity you need to move forward with confidence.
What is Double-Strand Sperm DNA Fragmentation and Why Does It Matter for Fertility
Think of sperm DNA as a ladder. A single-strand break (ssDB) is like one side rail being broken, which your body can often repair. A double-strand break (dsDB), however, is like both rails breaking at the same point. This severe damage is harder to repair and can lead to poor embryo development and a higher risk of recurrent miscarriage1,2.
By focusing on this specific, severe type of damage, the Extend test provides a precise evaluation that can uncover hidden issues. This critical insight allows you and your healthcare team to make more informed decisions and choose the most effective path to a successful pregnancy.
Who Should Consider the Extend® Test?
Early Recurrent Pregnancy Loss (RPL)
When experiencing multiple early miscarriages (within the first 12 weeks), the Extend test helps determine if elevated dsDB levels in sperm are contributing to pregnancy loss.
Planning IVF or ICSI
Understanding sperm DNA integrity can help you and your fertility specialist choose the best treatment path, such as IVF or ICSI, increasing the chances of success.
Surgical Sperm Retrieval (SSR) Candidates
Men undergoing SSR can assess sperm DNA quality to ensure suitability for ART procedures.
How the Extend Test Works
Extend® is non-invasive and validated for use with low sperm concentrations (oligozoospermic) and surgically retrieved sperm. This makes it suitable for a wide range of patients, including those not served by other SDF tests.
Why Choose Extend for Fertility Testing?
- Exclusive Focus: The only test that exclusively measures double-strand DNA breaks.
- Validated for Low Sperm Counts: Works with oligozoospermic and surgically retrieved samples.
- Actionable Insights: Helps couples and specialists make informed decisions for better outcomes.
Improving Outcomes with Advanced Techniques
While dsDBs are a fundamental issue, advanced sperm preparation techniques like microfluidic sperm selection for ICSI can enrich for sperm with healthier DNA, potentially improving treatment outcomes.
Book Your Extend® Test Today
Take the first step toward understanding your fertility.
Extend requires a referral from your doctor or fertility specialist.
Fast, reliable, and ISO-accredited testing.
Medical Research
- Drakeley A, Lunt RL, Newton E, et al. Double-stranded sperm DNA fragmentation assessed using Comet assay is associated with recurrent pregnancy loss. Reproductive BioMedicine Online. 2025. doi: 10.1016/j.rbmo.2025.105184. ↩︎
- Ribas-Maynou J, García-Peiró A, Encinas AF, et al. Double-stranded sperm DNA breaks, measured by Comet assay, are associated with unexplained recurrent miscarriage in couples without a female factor. PLoS ONE. 2012;7:e44679. doi: 10.1371/journal.pone.0044679. PMID: 23028579; PMCID: PMC3444447. ↩︎