What affects sperm health
Focusing on what affects sperm health can help you feel more in control and hopeful about improving your fertility journey.
There are four things your doctor looks at when assessing sperm quality:
- Count (how many sperm are present)
- Motility (how well they swim)
- Morphology (whether their shape is normal)
- DNA integrity (the genetic quality of the sperm itself)
All four matter, and a problem with any one of them can affect your chances of conception.
Several factors can affect your sperm quality. Heat is one of the most common factors that increases scrotal temperature. Regular use of hot tubs, tight underwear, and prolonged laptop use on your lap can all increase scrotal temperature and interfere with sperm production. Smoking is associated with higher levels of sperm DNA fragmentation and disrupts normal sperm function. Excessive alcohol has been linked to poor morphology and reduced semen volume. Obesity can increase oestrogen levels, raise scrotal temperature, and promote inflammation, all of which may negatively affect sperm health. Environmental exposures, including pesticides, heavy metals, and chemicals such as bisphenol A (BPA), may also contribute to reduced sperm quality.
The good news is that sperm are continuously produced, with a full cycle of sperm development taking around 74 to 90 days. This indicates that many lifestyle factors negatively affecting sperm quality are reversible. The positive changes you make today can significantly improve your improvement within three months.
Common causes of male infertility:
Male infertility rarely comes from one single cause. Here are the six most common reasons sperm quality or production is affected, along with potential solutions for each issue.
- Varicocele, enlargement of the veins within the scrotum, is one of the most common treatable causes of male infertility. It is found in around 35% of men who experience fertility difficulties. These swollen veins can increase scrotal temperature and create oxidative stress, which may affect sperm count, motility, and DNA integrity. The good news is that a varicocele can often be treated with a relatively straightforward surgical procedure, which may improve sperm quality in some men.
- Hormonal imbalances account for around 10 % of male infertility cases. Hormonal signals that tell the testes to produce sperm may become disrupted due to low testosterone levels, elevated prolactin levels, or an underactive thyroid. A simple morning blood test usually identifies the cause of infertility in males due to hormonal imbalances, and most hormonal causes respond well to treatment.
- Lifestyle factors may contribute to up to half of all cases and are often the most modifiable. Smoking, excessive alcohol consumption, obesity, anabolic steroid use, and chronic stress can disrupt the hormonal pathways involved in sperm production. The encouraging news is that positive lifestyle changes can make a difference. Because sperm production takes around three months, meaningful lifestyle changes can produce measurable improvements.
- Paternal age is increasingly recognised as an important factor. As men age, sperm quality can gradually decline. Research suggests that after the age of 40, sperm DNA fragmentation rises significantly, which may prolong the time it takes to conceive and increase the risk of certain health and developmental conditions in offspring.
- Genetic factors are less common causes of male infertility, but they are important to identify, particularly in men with very low or no sperm present in the ejaculate. Genetic testing is often used to diagnose conditions such as Klinefelter syndrome and Y-chromosome microdeletions.
Around 30-40% of cases remain unexplained even after a complete workup. However, this doesn’t mean they are untreatable; assisted reproduction options are still available and effective.
Fertility test for men: –
The fertility testing process involves four clear steps, each building on the previous one, to assess sperm health and identify potential issues accurately.
Step 1: – Semen Analysis
The first step is always to provide a sample. You will typically be asked to avoid ejaculation for 2 to 5 days before providing a semen sample, either at a clinic or at home, if the laboratory allows it. The laboratory will assess sperm count, motility (movement), morphology (shape), semen volume, and pH. Two separate analyses are usually recommended, since sperm quality can vary week to week. If the results appear normal but fertility treatment keeps failing, your doctor may add a sperm DNA fragmentation test to detect genetic damage that a routine semen analysis won’t catch.
Step 2: – Hormonal Panel
Ordered when there is an abnormal result on a semen analysis or the sperm count is very low. These tests are done with a single blood test, when testosterone levels are naturally at their highest, which will give us FSH, LH, testosterone, prolactin, TSH, and oestradiol, which all work together to tell us whether there is a problem related to sperm production within the testicle or in the hormone signals from the brain that regulate fertility.
Step 3: – Physical Examination
Fertility evaluation may also include a physical examination of your reproductive and urinary systems. During the examination, a urologist also checks the size, firmness, and enlarged veins within the scrotum (varicocele). The presence of the vas deferens is checked, and an ultrasound study of the scrotum is performed to evaluate for subclinical varicocele or other abnormalities that cannot be detected during a physical examination.
Step 4: – Genetic Testing
Recommended when sperm count is below 5 million/ml or no sperm is found at all. Karyotyping, Y-chromosome microdeletion testing, and CFTR mutation screening help identify the underlying cause and directly shape which treatment options are safe and appropriate for you.
Where to get tested in Singapore
Testing is more accessible than most men, except. You have three main routes depending on your budget and how quickly you want answers.
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The most affordable option is the public hospital route: –
o KK Women’s and Children’s Hospital (KKH)
o Singapore General Hospital (SGH)
o National University Hospital (NUH)
Many polyclinics offer fertility assessments. If you are seeking subsidised care, you will typically need a referral from a doctor at your local polyclinic before seeing a fertility specialist. A subsidised consultation at KKH starts from around SGD $45, rising to SGD $132–$164 at non-subsidised rates depending on the seniority of your consultant. Waiting times can be longer, but the clinical expertise is excellent.
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Private fertility clinics offer faster appointments and a more personalised experience.
o DTAP Clinic offers semen analysis at SGD $142 inclusive of GST, with sample collection available at the clinic or at home, provided the sample reaches the lab within two hours.
o Raffles Fertility Centre offers dedicated male fertility packages with follow-up consultations built in.
Across private clinics, costs typically range from SGD $100 to $300 for a standard semen analysis, with comprehensive packages including hormonal testing starting from SGD $200 and above.
- If you’re looking for an initial consultation with a general practitioner (GP), you can go to any GP clinic that provides semen analysis and hormone profiling. The GP should also be able to provide you with referrals to other specialists in your area if necessary.
On the day, you’ll provide a semen sample in a private room at the clinic or at home if permitted. Before the test, you should avoid ejaculation for 2 to 5 days and avoid using lubricants when collecting the sample. Results are usually ready within 1 to 3 days, followed by a consultation to walk you through what they mean.
Treatment options by cause: –
Treatment for male infertility is more targeted than many men expect. What works depends entirely on what’s causing the problem.
In cases of hormone-related infertility, medications are usually effective. Fertility issues caused by low testosterone, increased prolactin, or thyroid problems also respond well to hormone treatments. As hormone levels are restored to normal, sperm production will generally improve significantly.
Surgery is the primary treatment for a varicocele, one of the most common treatable causes of male infertility. The procedure consists of repairing or sealing the enlarged vein within the scrotum, helping to improve blood flow and reduce scrotal temperature. In many men, treatment leads to measurable improvements in sperm count, motility, and DNA integrity within three months of surgery.
Lifestyle-related infertility is often one of the most modifiable causes of infertility. Cutting out smoking, moderating alcohol, losing weight, and reducing stress can produce real improvements in sperm quality within 90 days, the time it takes for a full cycle of sperm production.
Once natural conception is no longer possible, assisted reproduction will be utilised. IUI can be performed on males with moderately low sperm counts; washed sperm is put directly into the uterus and has about a 10% success rate in male factor cases per treatment. In cases of significantly reduced sperm count, IVF with ICSI is the most viable option, as ICSI yields fertilisation and pregnancy success rates ranging from 35% to 45% per cycle in male factor conditions that would not allow for fertilisation through conventional means. Males with no sperm in their ejaculate can utilise surgical sperm retrieval in conjunction with ICSI as a method of achieving parenthood.
Age and male fertility: What the research shows
Male fertility doesn’t have a sharp cut-off the way female fertility does, but the idea that men can father children indefinitely without consequence isn’t accurate either.
Sperm quality begins to decline gradually from the mid-30s. The most significant change is in DNA integrity. A 2023 study found that men over 40 show a significant increase in sperm DNA fragmentation compared to younger men, 15% versus 9%, and a meaningful drop in DNA methylation levels, both of which affect embryo development and fertility treatment outcomes.
Research analysing over 6,800 sperm samples confirmed that volume, progressive motility, and total motility all decline significantly as paternal age advances, alongside rising DNA fragmentation. This is important because it takes longer to conceive, increases the risk of miscarriage, and affects IVF outcomes even when the female partner is young.
A 2024 study specifically recommended sperm DNA fragmentation testing for men with advanced paternal age, as standard semen analysis alone may miss the DNA-level changes that accumulate over time.
If you are over 40 years and planning to start or extend your family, asking your doctor about a DNA fragmentation test alongside standard semen analysis is a sensible, proactive step.
How couples should approach testing together
Fertility is rarely an issue that involves just one partner, and approaching it that way can lead to wasted time and delayed answers.
The 2024 AUA/ASRM guideline recommends that both partners be evaluated simultaneously from the very first appointment. Assessing male results without considering female factors provides an incomplete picture. This means that both partners should undergo testing at the same time, rather than waiting for the results from one before starting the other.
Testing both partners simultaneously leads to faster diagnosis, avoids unnecessary procedures, and allows treatment plans to be built around the complete reproductive picture rather than one side of it.
Emotionally, going through this together also makes a difference. Many men find fertility testing anxiety-provoking, but framing it as information-gathering rather than judgment tends to help. A single abnormal semen result is not a verdict; it’s a starting point.
In terms of timing, seek testing after 12 months of trying if you’re under 35, or after 6 months if your partner is over 35. If there’s a known risk factor, such as a varicocele, a history of STI, a history of chemotherapy, or irregular cycles on either side, don’t wait for those timelines. Earlier answers give you more options, not fewer.
Frequently Asked Questions
References:
Advanced Maternal Age in IVF: Still a Challenge? The Present and the Future of Its Treatment—PMC. (n.d.). Retrieved 1 May 2024, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6391863/
An Ultimate Guide To Fertility Tests in Singapore. (n.d.). Retrieved 22 June 2026, from https://blog.seedly.sg/fertility-tests-singapore/
Brannigan, R. E., Hermanson, L., Kaczmarek, J., Kim, S. K., Kirkby, E., & Tanrikut, C. (2024). Updates to Male Infertility: AUA/ASRM Guideline (2024). The Journal of Urology, 212(6), 789–799. https://doi.org/10.1097/JU.0000000000004180
Caroppo, E., & Colpi, G. M. (2023). Male Infertility: A Review of Key Papers Appearing in the Reproductive Medicine and Andrology Section of the Journal of Clinical Medicine. Journal of Clinical Medicine, 12(6), 2366. https://doi.org/10.3390/jcm12062366
Centre for Assisted Reproduction (CARE) | Singapore General Hospital. (n.d.). Retrieved 22 June 2026, from https://www.sgh.com.sg/content/singhealth-web/sgh/en/our-specialties/centre-for-assisted-reproduction-care.html
Escudé-Logares, L., Serrano-Novillo, C., Uroz, L., Galindo, A., & Márquez, C. (2024). Advanced Paternal Age: A New Indicator for the Use of Microfluidic Devices for Sperm DNA Fragmentation Selection. Journal of Clinical Medicine, 13(2), 457. https://doi.org/10.3390/jcm13020457
Frontiers | Increasing age in men is negatively associated with sperm quality and DNA integrity but not pregnancy outcomes in assisted reproductive technology. (n.d.). Retrieved 22 June 2026, from https://www.frontiersin.org/journals/aging/articles/10.3389/fragi.2025.1603916/full
Male Fertility Packages. (n.d.). Raffles Medical Group. Retrieved 22 June 2026, from https://www.rafflesmedicalgroup.com/services/specialist-centres/fertility/packages/male-fertility-test-packages/
Semen Analysis: Male Fertility Test Guide | Mediway. (2025, January 27). https://mediwaymedical.com/male-fertility-testing-in-singapore/
Semen Analysis Price: Understanding Costs Of Male Fertility Testing In Singapore—Health365. (n.d.). Retrieved 22 June 2026, from https://www.health365.sg/semen-analysis-price/
Semen Analysis, Sperm Count & Male Fertility. (2020, October 30). DTAP Medical Clinic | GP STD HIV Testing Clinic Singapore. https://www.dtapclinic.com/mens-health/semen-analysis-and-count-for-male-fertilty-test-singapore/
Anna Haotanto is the Founder of Zora Health and a passionate advocate for women’s empowerment. Anna’s personal experiences with egg-freezing, PCOS, perimenopause and the challenges of fertility have fueled her mission to provide high-quality information, financing, and support to help women and couples navigate their fertility journeys with confidence. She is also recognised for her achievements in finance, entrepreneurship, and women’s empowerment, and has been featured in various media outlets. You can also follow her on Linkedin or Instagram.
