Key takeaways:
- A SwimScore report is meant to be read as a set: the semen analysis shows what your sperm look like today, the DNA Fragmentation Index (DFI) shows whether the genetic cargo inside them is intact, and the hormone panel shows why your sperm production may be where it is.
- No single semen number diagnoses infertility, because a study of 765 infertile and 696 fertile men found extensive overlap between the two groups on concentration, motility, and morphology, with a wide "indeterminate" zone in between (Guzick et al., New England Journal of Medicine, 2001).
- Hormones tell you where a problem sits: in 153 men with no sperm in the ejaculate, 89% of those whose testes were not making sperm had an FSH above 7.6 mIU/mL or small testes, while 96% of those with a blockage did not (Schoor et al., Journal of Urology, 2002).
Last updated November 12, 2026.
When your results come back, the natural instinct is to scan for anything marked low and stop there. That is the least useful way to read a fertility report. A flag next to one number tells you very little on its own. The same sperm count can mean something completely different depending on what your motility, your DNA fragmentation, and your hormones look like next to it.
This guide walks through a SwimScore report the way we would read it ourselves: section by section first, then all together. We cover what each part measures, how much weight each number deserves, the common patterns and what they usually point to, and where the evidence is still thin. The goal is that you finish this page able to look at your own results and know which questions to ask next.
What Does a SwimScore Report Actually Measure?
A SwimScore Complete report has three parts: a semen analysis, a DNA Fragmentation Index, and a hormone panel. Each part answers a different question, and together they cover what a fertility specialist would usually want to see first.
The semen analysis is a lab test that counts sperm and measures how they move and how they are shaped. SwimScore reports sperm concentration (how many sperm are in each milliliter of semen), total sperm count (how many are in the whole sample), progressive motility (the share swimming forward), total motility (the share moving at all), and morphology (the share with a normal shape). Every sample is processed in a CLIA-certified lab, which means a lab held to the same federal quality standard as the labs your doctor uses, and our article on what a CLIA-certified lab is explains why that matters.
The DNA Fragmentation Index (DFI) is the percentage of sperm in your sample with broken or damaged DNA. A sperm can look and swim perfectly well and still carry damaged genetic material, which is why a standard semen analysis cannot measure this.
The hormone panel measures FSH, LH, and testosterone, alongside other hormones relevant to male fertility. These are the signals your brain and testes use to run sperm production, so they explain the "why" behind the semen numbers.
How Should You Read Your Semen Analysis Numbers?
Read each semen number by how far it sits from the WHO reference limit, not just by which side of the line it lands on. The limits are a shared ruler, not a pass or fail grade.
SwimScore assesses results against the WHO 6th Edition, the World Health Organization's 2021 laboratory manual for semen analysis. Its lower reference limits are a sperm concentration of 16 million per mL, a total sperm count of 39 million per ejaculate, a total motility of 42%, and 4% normal forms by strict criteria, with a progressive motility of 30% (Boitrelle et al., Life, 2021). You will often see 32% quoted for progressive motility, including on older SwimScore pages; that figure comes from the earlier 5th Edition (Cooper et al., Human Reproduction Update, 2010). The two differ by about two percentage points, which is smaller than the normal swing between two samples from the same man.
These limits were set at the 5th centile of men whose partners conceived within 12 months. In plain terms, about 1 in 20 men who had recently fathered a child still fell below each line. Our explainer on where the WHO 6th Edition thresholds come from goes through this in detail.
The best evidence that a single cutoff cannot sort fertile from infertile men comes from a large American study. Researchers compared two semen samples each from 765 men in infertile couples and 696 men in fertile couples across 9 sites. They found that a concentration below 13.5 million per mL, motility below 32%, or morphology below 9% placed a man in a "subfertile" range, while values above 48 million per mL, 63%, and 12% placed him in a "fertile" range. Everything between those two sets of numbers was indeterminate, and the authors concluded that none of the measures was diagnostic of infertility on its own (Guzick et al., New England Journal of Medicine, 2001).
The practical lesson is to look at distance and direction. A concentration of 14 million per mL is a very different finding from 2 million per mL, even though both are flagged as low. One number slightly under its line with everything else solid is a different situation from several numbers well under theirs.
Which Semen Number Matters Most?
For predicting natural conception and choosing a treatment route, the most useful single figure is usually your total motile sperm count (TMSC), which combines volume, concentration, and motility into one number. TMSC is the total number of moving sperm in the whole sample.
In a Dutch study of 1,177 couples with male-factor or unexplained infertility followed for up to 3 years, TMSC predicted the chance of a natural ongoing pregnancy better than the WHO categories did. The authors proposed three groups: below 5 million, 5 to 20 million, and above 20 million moving sperm (Hamilton et al., Human Reproduction, 2015). Our full article on total motile sperm count and what it means for IUI, IVF, and ICSI explains how clinics use these bands.
Morphology deserves less weight than many men give it. It discriminated best between fertile and infertile men in the Guzick study, but it is also the hardest number for labs to measure consistently. Our piece on what sperm morphology actually tells you covers why a low morphology score alone rarely changes the plan. If your report uses terms like oligozoospermia or asthenozoospermia, our guide to what each of those labels means translates them into plain English.
What Does Your DNA Fragmentation Index Add?
Your DNA Fragmentation Index tells you whether the genetic material inside your sperm is intact, which a standard semen analysis cannot see. SwimScore reports DFI in three bands: below 15% is good, 15% to 30% is moderate, and above 30% is high.
High DNA fragmentation has been linked most consistently with pregnancy loss. A 2012 meta-analysis of 16 cohort studies covering 2,969 couples found that men with high DNA fragmentation had about twice the risk of their partner miscarrying, with a risk ratio of 2.16 (Robinson et al., Human Reproduction, 2012). A risk ratio of 2.16 means the miscarriage rate was a little over double in that group compared with men with low fragmentation.
The American Urological Association and American Society for Reproductive Medicine (AUA/ASRM) guideline does not recommend DNA fragmentation testing in every man's first evaluation, but it does recommend it, along with a chromosome test, for men whose partners have had recurrent pregnancy loss (Schlegel et al., Journal of Urology, 2021). We include it in SwimScore Complete because a high DFI often sits behind an otherwise normal semen analysis, as we explain in high DNA fragmentation with a normal semen analysis. For what typically drives a high result, including varicocele, smoking, heat, and age, see what causes high sperm DNA fragmentation.
How Do Your Hormones Explain Your Semen Results?
Your hormones show where in the sperm production chain a problem sits. That chain is called the HPG axis: the hypothalamus in your brain signals the pituitary gland, and the pituitary signals the testes. When the testes are struggling, the brain shouts louder, and that shouting shows up as high hormone levels.
FSH, or follicle-stimulating hormone, is the pituitary's signal to the parts of the testes that support sperm development. A typical adult male range is about 1.0 to 7.6 mIU/mL. A high FSH usually means the testes are not responding well and the brain is pushing harder to compensate. In a study of 213 men who had testicular biopsies, average FSH was 3.0 IU/L in men with normal sperm-producing tissue and 16.0 IU/L in men whose testes contained no sperm-producing cells at all. The same authors cautioned that a normal FSH does not rule out a serious production problem (Bergmann et al., Clinical Endocrinology, 1994). Our article on what your FSH level is telling you covers this in full.
LH, or luteinizing hormone, is the pituitary's signal to the cells that make testosterone, with a typical adult range of about 1.5 to 9.3 mIU/mL. Read alongside testosterone, it tells you whether a low testosterone result starts in the testes or in the brain. Low testosterone with high LH points to the testes, called primary hypogonadism. Low testosterone with low or normal LH points to the brain's signaling, called secondary hypogonadism. In a survey of 3,369 European men aged 40 to 79, 11.8% fit the secondary pattern and 2.0% fit the primary pattern (Tajar et al., Journal of Clinical Endocrinology and Metabolism, 2010). We break down both patterns in low testosterone with high LH versus low or normal LH, and the AUA guideline on testosterone deficiency uses a total testosterone below 300 ng/dL, confirmed on two separate early-morning blood draws, as its working definition of low (Mulhall et al., Journal of Urology, 2018).
One pattern deserves its own warning. If your LH and FSH are near zero and your testosterone is normal or high, the most common explanation in men of reproductive age is testosterone from outside the body, such as TRT or anabolic steroids. External testosterone tells the brain to stop sending LH and FSH, and sperm production can collapse as a result. Our article on TRT-induced infertility explains the mechanism.
How Do You Read the Semen Analysis and Hormone Panel Together?
Read them as one story: the semen analysis tells you what is happening, and the hormones tell you why. A few common combinations cover most of what men see.
A normal semen analysis with normal hormones and a low DFI is the reassuring result. It does not guarantee a pregnancy, because conception also depends on your partner's fertility, timing, and chance, but it means the male side shows no obvious red flags. If you are still not conceiving after a year, our article on what a normal semen analysis does not rule out covers the next questions.
A low sperm count with high FSH usually points to a production problem inside the testes. The brain is signaling hard and the testes are not keeping up. This pattern is worth taking to a urologist, because causes range from varicocele, an enlarged vein around the testis that is treatable, to genetic conditions that are worth knowing about before planning treatment.
A low sperm count with low or normal FSH and LH, plus low testosterone, points upstream to the brain's signaling. This matters because signaling problems are often treatable with medication that restarts the hormone signals, under a specialist's care, rather than with testosterone itself.
A very low or zero count with normal FSH and normal-sized testes can point to a blockage rather than a production problem. In 153 men with no sperm in the ejaculate, 96% of those with a blockage had an FSH of 7.6 mIU/mL or less or a testis longer than 4.6 cm, while 89% of those whose testes were not making sperm had a higher FSH or smaller testes (Schoor et al., Journal of Urology, 2002). Our article on obstructive versus non-obstructive azoospermia covers what each means for your options.
A normal semen analysis with a high DFI is the pattern a standard test would miss entirely. It is especially relevant for couples who have had a miscarriage or a failed IVF cycle, and it often has a fixable cause worth looking for.
What We Are More Skeptical About
We are skeptical of any decision made on a single semen sample. Sperm counts swing a great deal from one sample to the next in the same man. In a study of 74 infertile men and 65 donors who each gave at least five samples, the sample-to-sample variation in sperm count was about 54% in the patients and 46% in the donors, and the author concluded that at least three samples were needed for a reliable picture (Keel, Fertility and Sterility, 2006). The AUA/ASRM guideline advises at least two analyses, ideally a month apart, especially when the first is abnormal (Schlegel et al., Journal of Urology, 2021). Our piece on test-retest variability explains why.
We are also cautious about treating DFI bands as precise cutoffs. DFI results depend on which lab method was used, and the published thresholds were built on specific methods. A 2021 expert review of DNA fragmentation testing rated much of the supporting evidence as moderate to low quality, and two of its authors had commercial interests in fragmentation testing (Esteves et al., Andrologia, 2021). We think DFI is worth measuring, and we also think a result of 28% and one of 32% are closer together than the band labels suggest. Our comparison of DNA fragmentation testing methods covers the differences.
Finally, no single result predicts a pregnancy. Improving a semen number or a hormone level has not been shown in controlled trials to reliably improve pregnancy or live-birth rates, because pregnancy depends on far more than any one measure, including your partner's age and fertility. Your results tell you where to focus. They do not forecast the outcome.
How Should You Think About Your Results Practically?
Start with the overall pattern, not the single worst number. Look at your TMSC, your DFI, and whether your FSH, LH, and testosterone are in range, and ask whether they tell a consistent story. If everything is in range, that is genuinely good news, and the next step is usually time and timing rather than more testing.
If one number is borderline and the rest look solid, retest before you act. If you are making a change in the meantime, such as stopping smoking, cutting back on alcohol, losing weight, or avoiding heat, allow at least 12 weeks before retesting, because a full cycle of sperm production takes about 72 days. Our articles on heat exposure, alcohol, and obesity explain what each change can and cannot do.
If several numbers are well below their limits, if FSH is high, if testosterone is low, or if you see no sperm at all, take the full report to a urologist or a reproductive specialist. Bring both the semen analysis and the hormone panel, because together they save a round of testing and point the clinician in the right direction. Semen quality is also a broader health signal: in a study of 11,935 American men followed for an average of 7.7 years, men with two or more abnormal semen parameters had 2.3 times the risk of death of men with normal results, after accounting for other health conditions (Eisenberg et al., Human Reproduction, 2014). That is an association, not proof that semen quality causes poor health, but it is one more reason not to ignore an abnormal result.
If you are on testosterone or thinking about starting it, read our guide on what to test before starting TRT before you make that decision, because the AUA guideline states that testosterone therapy should not be prescribed to men who are currently trying to conceive (Mulhall et al., Journal of Urology, 2018).
Our Take
We know that no single semen number decides fertility, that the WHO 6th Edition limits are a shared ruler rather than a verdict, and that hormones explain where a problem starts. We know that DNA fragmentation adds information a standard semen analysis cannot, especially for couples who have experienced a miscarriage. We also know that one sample is a snapshot, not a diagnosis.
What we do not know is exactly where the line sits between men who will and will not conceive, and we cannot promise that improving any number will lead to a pregnancy. We still think reading your full set of results carefully is one of the most useful things you can do. It tells you whether to wait, retest, change something, or see a specialist, and it stops you from being either falsely reassured or needlessly alarmed by a single flag.
Know your numbers, read them as a set, retest before you act, and bring the whole picture to a clinician if anything looks off. If you have not tested yet, SwimScore Complete measures sperm concentration, progressive motility, total motility, morphology, DNA Fragmentation Index (DFI), and a hormone panel from home, all processed in a CLIA-certified lab. If you are testing as a couple, our couples page explains how SwimScore fits alongside your partner's workup.
FAQ
How do I read my semen analysis results?
Compare each number with its WHO 6th Edition lower reference limit, look at how far above or below it sits, and read the numbers together rather than one at a time. No single semen number diagnoses infertility, because fertile and infertile men overlap widely (Guzick et al., New England Journal of Medicine, 2001).
What are normal semen analysis values?
The WHO 6th Edition lower reference limits are 16 million sperm per mL, 39 million sperm per ejaculate, 42% total motility, 30% progressive motility, and 4% normal forms (Boitrelle et al., Life, 2021). Falling below one of these limits does not by itself mean you cannot conceive.
Why should I test my hormones as well as my sperm?
Hormones show where a sperm problem starts. A high FSH points to the testes, while low FSH and LH with low testosterone point to the brain's signaling, and each leads to a different treatment conversation.
What is a good DNA fragmentation result?
SwimScore reports a DNA Fragmentation Index below 15% as good, 15% to 30% as moderate, and above 30% as high. High fragmentation is linked to about twice the risk of miscarriage (Robinson et al., Human Reproduction, 2012).
Should I repeat my semen analysis?
Yes, if any result is abnormal or borderline. Sperm counts vary a great deal between samples, and guidelines advise at least two analyses, ideally a month apart (Schlegel et al., Journal of Urology, 2021).
References
- Guzick DS, et al. Sperm morphology, motility, and concentration in fertile and infertile men. New England Journal of Medicine. 2001. https://pubmed.ncbi.nlm.nih.gov/11794171/
- Schoor RA, et al. The role of testicular biopsy in the modern management of male infertility. Journal of Urology. 2002. https://pubmed.ncbi.nlm.nih.gov/11743304/
- Boitrelle F, et al. The Sixth Edition of the WHO Manual for Human Semen Analysis: A Critical Review and SWOT Analysis. Life. 2021. https://pubmed.ncbi.nlm.nih.gov/34947899/
- Cooper TG, et al. World Health Organization reference values for human semen characteristics. Human Reproduction Update. 2010. https://pubmed.ncbi.nlm.nih.gov/19934213/
- Hamilton JA, et al. Total motile sperm count: a better indicator for the severity of male factor infertility than the WHO sperm classification system. Human Reproduction. 2015. https://pubmed.ncbi.nlm.nih.gov/25788568/
- Robinson L, et al. The effect of sperm DNA fragmentation on miscarriage rates: a systematic review and meta-analysis. Human Reproduction. 2012. https://pubmed.ncbi.nlm.nih.gov/22791753/
- Schlegel PN, et al. Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline Part I. Journal of Urology. 2021. https://pubmed.ncbi.nlm.nih.gov/33295257/
- Bergmann M, et al. Serum FSH and testicular morphology in male infertility. Clinical Endocrinology. 1994. https://pubmed.ncbi.nlm.nih.gov/8306472/
- Tajar A, et al. Characteristics of secondary, primary, and compensated hypogonadism in aging men: evidence from the European Male Ageing Study. Journal of Clinical Endocrinology and Metabolism. 2010. https://pubmed.ncbi.nlm.nih.gov/20173018/
- Mulhall JP, et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline. Journal of Urology. 2018. https://pubmed.ncbi.nlm.nih.gov/29601923/
- Keel BA. Within- and between-subject variation in semen parameters in infertile men and normal semen donors. Fertility and Sterility. 2006. https://pubmed.ncbi.nlm.nih.gov/16412742/
- Esteves SC, et al. Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations. Andrologia. 2021. https://pubmed.ncbi.nlm.nih.gov/33108829/
- Eisenberg ML, et al. Semen quality, infertility and mortality in the USA. Human Reproduction. 2014. https://pubmed.ncbi.nlm.nih.gov/24838701/
Fertility clinics and urology practices: if you want patients to arrive with a semen analysis, DNA Fragmentation Index, and hormone panel already in hand, all from a CLIA-certified lab, see how SwimScore can support your workflow on our clinic page.
This article is for general education and is not medical advice. Your own results should be reviewed with a physician who can interpret them alongside your history and your partner's.
SwimScore uses CLIA-certified labs for all semen analysis and hormone testing, assessed against WHO 6th Edition clinical thresholds.
