Sperm DNA fragmentation: Why it's now being considered in evaluation, treatment of recurrent miscarriage

When a couple experiences recurrent pregnancy loss, doctors usually look at several possible causes, including chromosomal abnormalities, problems with the uterus, and certain maternal health conditions.

But newer guidance is also putting attention on a possible male factor: damage to the DNA inside sperm.

The American Society for Reproductive Medicine (ASRM), in its 2026 practice committee opinion on recurrent pregnancy loss (RPL), says sperm DNA fragmentation testing may be considered in patients with otherwise unexplained recurrent miscarriage or recurrent miscarriage accompanied by infertility.

However, the group also says more research is needed to determine whether treating elevated sperm DNA fragmentation can actually improve pregnancy outcomes.

This does not mean sperm DNA fragmentation testing is now a routine test for everyone who has experienced a miscarriage. Rather, it is being considered as one possible part of the evaluation when recurrent losses remain unexplained.

What is recurrent pregnancy loss?

ASRM defines recurrent pregnancy loss as the spontaneous loss of two or more pregnancies, excluding confirmed molar or ectopic pregnancies.

The organization recommends a stepwise evaluation, starting with chromosome analysis of miscarriage tissue when feasible, followed by additional testing depending on the findings.

This is important because many early miscarriages are caused by chromosomal abnormalities. ASRM says about 50% to 60% of first-trimester miscarriages are due to embryonic aneuploidy, or an abnormal number of chromosomes.

But when recurrent losses cannot be explained by these common causes, doctors may need to look at other factors, including the sperm.

What is sperm DNA fragmentation?

Sperm DNA fragmentation refers to breaks or damage in the genetic material carried by sperm. Sperm DNA is tightly packaged and protected, but some areas remain susceptible to damage.

According to ASRM, sperm DNA damage may be associated with factors such as environmental toxins, pollution, certain drugs, fever or illness, cigarette smoking, varicocele, and increasing paternal age.

Some DNA damage can be repaired by the egg after fertilization, but damage that is too extensive may be linked to poorer reproductive outcomes.

A sperm DNA fragmentation test measures the amount of sperm carrying this type of DNA damage.

Why is it being considered in recurrent miscarriage?

There is growing evidence linking higher sperm DNA fragmentation with miscarriage.

A 2019 systematic review and meta-analysis published in the Fertility and Sterility journal looked at 15 prospective studies involving 579 male partners of women with recurrent pregnancy loss and 434 male partners of fertile controls. The researchers found that men whose partners had recurrent pregnancy loss had significantly higher sperm DNA fragmentation than men in the fertile control group.

The study's pooled analysis found a significantly higher rate of sperm DNA fragmentation among male partners of women with recurrent pregnancy loss, although there was considerable variation among the studies. Thus, further studies are needed.

ASRM's 2026 review similarly cites meta-analyses showing that male partners of women with recurrent pregnancy loss had sperm DNA fragmentation scores about 11% to 12% higher than partners of fertile controls.

Another meta-analysis found that couples with high sperm DNA fragmentation had a higher rate of subsequent miscarriage than those with low fragmentation, with a relative risk of 2.16.

Does high sperm DNA fragmentation cause miscarriage?

Not necessarily.

This is one of the most important distinctions in the current evidence.

The 2019 systematic review found an association between sperm DNA fragmentation and recurrent pregnancy loss, but the researchers specifically said that an association does not prove that DNA fragmentation causes the pregnancy losses.

They also noted considerable differences among the studies, including the tests used, how recurrent pregnancy loss was defined, whether fresh or frozen semen was examined, and whether the participants also had infertility.

ASRM's 2026 guidance reflects the same caution. While it recognizes the association between elevated sperm DNA fragmentation and miscarriage, it says there are still no well-controlled published studies showing that treating elevated sperm DNA fragmentation reduces the risk of recurrent pregnancy loss.

So, when might the test be considered?

Based on the 2026 ASRM guidance, sperm DNA fragmentation testing may be considered when recurrent miscarriages remain unexplained, or when recurrent miscarriage occurs alongside infertility.

If the test shows elevated fragmentation, ASRM lists reproductive urology evaluation as a treatment option with limited or conflicting evidence.

The test therefore should not be viewed as a replacement for the standard recurrent pregnancy loss workup.

Instead, it can provide another piece of information, particularly when other evaluations have not identified an explanation.

What happens if the test is abnormal?

An abnormal result does not automatically mean that a couple will miscarry again, nor does it establish that the sperm is responsible for previous losses.

ASRM notes that some interventions, including varicocele repair, sperm selection, smoking cessation, changes in ejaculation frequency and other lifestyle measures, have been shown to reduce sperm DNA fragmentation.

However, evidence that these approaches actually reduce recurrent pregnancy loss remains insufficient.

For now, the focus is on identifying possible male reproductive factors and determining whether there is an underlying issue that can be addressed.

—CDC, GMA News