What is sperm DNA fragmentation?

Sperm DNA fragmentation refers to breaks in the genetic material carried by sperm. Testing assesses a semen sample for evidence of this damage. Reports commonly express fragmentation as a percentage, sometimes called the DNA fragmentation index, or DFI.

The sample is collected in a similar way to a routine semen analysis. The DNA assessment itself takes place in the laboratory; it does not involve a surgical procedure. [1]

If you have not yet had an initial sperm assessment, explore semen analysis at MDC and discuss whether additional testing is needed.

Who should consider testing?

This is a decision to make with a fertility clinician. Professional guidance differs, so testing should not be presented as a routine requirement for every man trying to conceive.

Before paying for a test, ask: “What would you recommend if my result is high, and would that recommendation differ if it is low?” This helps establish whether testing has a useful role in your care.

If you need specialist advice first, visit MDC’s urology and andrology service to enquire about an appointment.

Which DNA fragmentation method is best?

Laboratories use different methods, including sperm chromatin dispersion (SCD), sperm chromatin structure assay (SCSA), TUNEL and Comet testing. Their methods and interpretation differ, so percentages should not be treated as interchangeable. [3]

MDC’s published fertility packages list “Halo sperm” DNA fragmentation testing. Halosperm uses the SCD technique, which assesses chromatin dispersion patterns after laboratory processing. Ask the team to confirm the method used for your appointment. [4]

For follow-up, ask whether the same method and comparable collection conditions should be used. A useful report should identify the method and explain the laboratory’s interpretation.

Questions to ask before booking in London

1. Why has testing been suggested? Establish the clinical question before choosing a package.
2. Which method will the laboratory use? Confirm whether your fertility specialist can interpret that method.
3. What preparation is required? Request instructions for abstinence, collection and sample delivery.
4. What does the price include? Check whether semen analysis, a written report and a consultation are included or charged separately.
5. When will the complete report be available? Different components of a combined package may have different reporting times.
6. Who will explain the result? Agree how the findings will be shared with your treating clinician.

MDC testing and booking options

MDC offers a standalone DNA fragmentation test and combined fertility packages. Use the links below to explore the relevant service and its booking options. Confirm current inclusions, prices and availability before payment.

How should I prepare for my sample?

Request the instructions for your specific appointment before attending. MDC’s DNA fragmentation listing specifies 2–5 days without ejaculation, but preparation can differ between services. Follow the instructions confirmed by the laboratory.

Ask whether you should produce the sample at the centre and what arrangements apply if collecting elsewhere. Do not assume that a home-collected or posted sample will be suitable.

Bring relevant previous semen or DNA fragmentation reports and any instructions from your fertility clinic. Tell the team about recent illness and medicines, and do not stop prescribed treatment without advice.

What does the result mean?

A higher fragmentation result is not a diagnosis of permanent infertility. Equally, a low result does not guarantee pregnancy. Interpretation depends on the method, the laboratory’s reference information and the wider fertility assessment.

Avoid comparing your report with a generic online “good, fair, poor” chart. Published thresholds vary between methods, and these tests do not reliably predict an individual couple’s treatment outcome. [3]

If the result is raised, ask your specialist whether it changes the plan. Repeat testing, supplements or a change in fertility treatment should have a clear rationale; measuring a change in fragmentation is not the same as proving an improved chance of a live birth. [2]

Frequently asked questions