The Role of Male Fertility in Conceiving: What You Need to Know

Discussions around fertility often focus on women—menstrual cycles, hormones, and egg quality—but conception is a two-way street, and male fertility is just as essential. In fact, male-factor infertility contributes to roughly 50% of all infertility cases.¹ Yet despite its prevalence, it's frequently overlooked in both public discourse and media coverage. Male infertility is a multifactorial condition, influenced by genetics, lifestyle, environmental exposures, age, and medical history.² Misconceptions persist, highlighting the need for more awareness, accurate information, and open conversation about male reproductive health. 

Myth #1: If a man can ejaculate, he's fertile. 

Reality: Ejaculation doesn't necessarily guarantee healthy sperm. Semen can lack sufficient sperm, or the sperm may have poor motility or abnormal shapes. Lifestyle factors can significantly affect sperm quality. Smoking, for example, is strongly linked to lower sperm count and motility, worse morphology, and increased DNA fragmentation.³ One study found that chronic smokers had significantly reduced semen volume and total sperm count compared to non-smokers.³ Beyond smoking, alcohol has also been found to be a significant detriment, associated with hormonal disruption and reduced sperm concentration and motility.4 

Myth #2: Male fertility doesn't decline with age. 

Reality: While men do not experience menopause, semen quality does decline with age. A comprehensive meta-analysis of 90 different studies involving over 90,000 men found consistent age-related decreases in semen volume, sperm concentration, motility, and morphology.5 The analysis also indicated that DNA fragmentation tends to increase with age, potentially affecting fertilization, embryo development, and the success of pregnancy.5 These changes become more pronounced after age 40, though subtle declines may begin even earlier. Advancing paternal (and maternal) age is associated with longer time to conception, higher miscarriage risk, and increased rates of chronic conditions in offspring.6 

Myth #3: If there's trouble conceiving, the problem is usually on the woman's side. 

Reality: This is a harmful misconception. Male-factor infertility accounts for about 50% of all infertility cases.¹ Unfortunately, men are often under-tested—especially in cases labeled as "unexplained" infertility—leading to male factors being frequently overlooked in a couple's infertility journey. At the Center for Human Reproduction (CHR), we view "unexplained" more as a placeholder than a true diagnosis; there is always an underlying cause—it just may require more thorough investigation to uncover. 

Subtle factors often affecting male fertility, such as hormonal imbalances, genetic issues, or environmental exposures, can be missed during routine screenings. Without comprehensive evaluation, these causes can remain hidden, delaying effective treatment. Leading experts stress that timely and thorough evaluation of male fertility is just as vital as evaluating female fertility for accurate diagnosis and effective treatment planning.7 Early identification enables couples to pursue targeted interventions sooner—improving their chances of conception while reducing emotional and financial strain. 

Understanding these common misconceptions is the first step toward a more informed approach to fertility. 

What Really Impacts Sperm Health? 

Smoking: Impairs sperm count, motility, morphology, and increases DNA damage.³ 

Age: Sperm quality gradually declines beginning around age 40.4  

Heat and lifestyle: Overheating (from saunas, laptops on laps, tight underwear), obesity, and poor diet can all reduce sperm quality.5

Environmental factors: Living in high pollution areas and long-term exposure to outdoor air pollution are linked with poorer semen quality, including lower semen volume, sperm concentration, motility, morphology, and increased DNA fragmentation.6  

Medical conditions: Varicocele, a cause of infertility that affects 15% of healthy men and 25% of men with abnormal semen analysis, is a dilation of veins within the scrotum that disrupts temperature regulation and impairs sperm quality. Other medical conditions—such as reproductive tract infections, hormonal imbalances, and diabetes, among others—can also interfere with sperm production, function, or transport.¹ 

How to Support Male Fertility 

The good news? Many male fertility factors are modifiable. Here are some science-backed ways to improve sperm health: 

Quit smoking—improvements can begin in just 3 months.³ 

Reduce exposure to heat (avoid hot tubs, tight underwear, laptops on your lap). 

Exercise regularly and maintain a healthy weight.5 

Eat a nutrient-rich, antioxidant-heavy diet (think: leafy greens, healthy fats, vitamins C & E, zinc). 

Limit exposure to air pollution when possible.6 

Treat underlying medical conditions, like varicocele.7 

When Should You Get Tested? 

If you've been trying to conceive for 6 months (if over 35) or 12 months otherwise without success, both partners should be evaluated. A semen analysis is a simple and essential first step in understanding male fertility.7 As noted by experts in reproductive medicine, thorough male evaluation is often overlooked but critical to guiding appropriate treatment.8 

The Bottom Line 

Male fertility is a vital part of the reproductive picture, not an afterthought. With better awareness, early testing, and evidence-based care, couples can approach conception with greater clarity and confidence. Fertility challenges affect both partners, and men have more influence over their reproductive health than many realize. Small changes can make a big difference—and support a more informed, proactive path to parenthood. 

References 

1. Agarwal A, Baskaran S, Parekh N, et al. Male infertility. Lancet. 2021;397(10271):319-333. doi:10.1016/S0140-6736(20)32667-2 
2. Agarwal A, Mulgund A, Hamada A, Chyatte MR. A unique view on male infertility around the globe. Reprod Biol Endocrinol. 2015;13:37. doi:10.1186/s12958-015-0032-1 
3. Osadchuk L, Kleshchev M, Osadchuk A, et al. Effects of cigarette smoking on semen quality, reproductive hormone levels, metabolic profile, zinc, and sperm DNA fragmentation in men. Front Endocrinol (Lausanne). 2023;14:1255304. doi:10.3389/fendo.2023.1255304 
4. Jensen TK, Gottschau M, Madsen JO, et al. Habitual alcohol consumption associated with reduced semen quality and changes in reproductive hormones. BMJ Open. 2014;4(9):e005462. doi:10.1136/bmjopen-2014-005462 
5. Johnson SL, Dunleavy J, Gemmell NJ, Nakagawa S. Consistent age-dependent declines in human semen quality: a systematic review and meta-analysis. Ageing Res Rev. 2015;19:22-33. doi:10.1016/j.arr.2014.10.007 
6. Margiana R, Odhar HA, Prasad KD, et al. Does outdoor air pollution cause poor semen quality? A systematic review and meta-analysis. BMC Urol. 2025;25:50. doi:10.1186/s12894-025-01728-4 
7. Practice Committee of the American Society for Reproductive Medicine. Diagnostic evaluation of the infertile male: a committee opinion. Fertil Steril. 2021;117(2):278-285. doi:10.1016/j.fertnstert.2021.01.012 
8. Gleicher N, Barad DH. Male infertility: why so little progress? Fertil Steril. 2011;95(3):813-815. doi:10.1016/j.fertnstert.2010.12.041