A woman's fertility decreases with age. While everyone seems familiar with this concept, most of us tend to ignore men. Speaking on biological terms, women have a limited reserve of eggs, and men, on the other hand, produce millions of sperms every day.1 However, this doesn't confer men with lifelong fertility! Recent studies suggest that a man is solely responsible for 20% of infertility cases and may act as a contributing factor in another set of 30-40% cases.2 So, even when there's no risk of 'running out' of sperms, why is male infertility on an all-time rise? Is it the risk of an underlying medical condition, low sperm quality, or some other factor we aren’t even aware of?

Low Sperm Quality With Progressing Age

Age plays a significant role in declining male fertility.3 But there can be other reasons to it, and they differ from one person to another. Right from our environment to the kind of lifestyle we follow, each factor contributes to our ability to reproduce.3  With progressing age, men are also at an increased risk of developing medical conditions like erectile dysfunction (a medical condition defined by having difficulty with developing or maintaining an erection during sexual intercourse), prostrate (the gland that produces fluids to aid nourishment & transportation of sperm) cancer, or testicular (a pair of glands located inside the scrotum that produce sperms) cancer that may lead to low sperm quality. 3, 4, 5 

Let's understand how that happens.

The ‘Biological Clock’ For Men

Yes. It does exist. Men have a biological clock too! The stories of celebrities fathering children in their 70s, 80s, or even 90s may sound fascinating, but these are some very strong exceptions! As men age, their sperm ages too, and the sperm quality starts to decline as they hit 40.6  This comes as a big challenge for our generation that’s less interested in embracing fatherhood before their late 30s or early 40s.

Biological clock in menBiological clock in men

What Causes Decline In Sperm Quality?

As discussed before, with progressing age and factors like diseases, environment & lifestyle choices kicking in, male fertility goes downhill after 40.6 The ultimate result -  low sperm quality! But what exactly goes wrong with your sperm after a certain age? Here's the answer.

1. Reduced Sperm Motility

The motility of your sperm allows it to travel through the vagina, cervix, and all the way to the fallopian tube to meet the egg. But studies highlight that even if you are a young, healthy male who keeps those cigarettes away, your sperm motility will continue to decrease by 0.8% every year.7 The sperm acquires its motility when it passes through the prostate gland & the epididymis, as it makes its journey through the male reproductive tract. With age, these glands lose their function, causing decreased motility in your sperm. 8

2. Reduced Sperm Count & Concentration

Sperm count refers to the number of sperm released in one ejaculation, whereas sperm concentration refers to the number of sperm/ml of semen. To get a woman pregnant, a man needs a minimum of 16 million sperm/ml of semen.9 As for the decline of sperm count with age, there is comparatively lesser data to highlight the trend clearly. However, some studies report that sperm concentration can see a decline of 3.3% as you turn a year old.3

3. Abnormal Sperm Morphology

Morphology of the sperm refers to its standard structure, size, and shape. With age, the number of sperms with a normal, or let's say proper morphology, decreases. This decline stands roughly around 2.2% with each passing year.10 And as you would guess, the chances for an abnormal sperm to fertilize an egg are extremely low.11

4. DNA Fragmentation

The majority of men aren't familiar with the concept of DNA fragmentation. Yet, it is quite an 'influential factor' in dictating your fertility, especially in later years. To define it simply, DNA fragmentation refers to the amount of DNA damage in your sperm. Although men of all ages undergo DNA fragmentation 3, its rate starts to increase by 0.3%/year as you age.12

Other Effects Of Advancing Male Age

Along with low sperm quality and reduced fertility rates, advanced paternal age can pose many other problems related to pregnancy & the offspring. The most common issue seen among aging males as fathers is miscarriages. The chances of pregnancy loss within 6-20 weeks with a >35-year-old father are 27%. And this rate increases even more as they cross 50.13

Increased risk of miscarriage, pre-term-birth, multiple birth defects, and neurodevelopmental diseasesIncreased risk of miscarriage, pre-term-birth, multiple birth defects, and neurodevelopmental diseases

Statistics also point to an increased incidence of preterm birth by 1.7-2.1% if the father is above 45 years of age.13 Moreover, men between 30-35 years of age are more likely to have babies being born with birth defects than fathers in their early 20s. The risk again increases many folds, 16% to be precise, as they turn 50!13

Apart from these adverse pregnancy outcomes, advanced paternal age is also linked with an increased risk of neurodevelopmental disorders in children, including schizophrenia, autism, and psychosis.13

It's Time To Track Your Fertility!

We can't stop the clock, but we can learn to move with it without giving up a chance to have a baby! And the only way to do that is to opt for a semen analysis. And the sooner, the better. Because let's not forget what we just learned - Male fertility begins to decrease after 35. It may start a little early for some, and for others, it may go up to 40 or more. Does that mean all 20 or 25-year-olds should sit back and relax? Definitely no! 

Take A Step Ahead With SpermScore

A semen analysis test is the best way to understand your fertility and take actionable steps in time. It gives you a detailed perspective on your sperm health and also helps couples to navigate through fertility testing with ease, saving both cost & time. LifeCell is here to help you take a step towards this journey with SpermScore - A convenient, comprehensive & confidential way to test the quality of your sperm in the comfort and privacy of your home! With just a single test, you can understand your fertility status, plan your family goals, and explore options like sperm banking, if necessary!


  1. https://www.ncbi.nlm.nih.gov/books/NBK279031/ 
  2. https://www.ncbi.nlm.nih.gov/books/NBK562258/  
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3253726/ 
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321353/ 
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270136/ 
  6. https://www.cdc.gov/reproductivehealth/infertility/index.htm 
  7. https://pubmed.ncbi.nlm.nih.gov/16793993/ 
  8. https://www.tandfonline.com/doi/abs/10.1080/01485010701225667?journalCode=iaan19 
  9. https://www.nhs.uk/conditions/low-sperm-count/  
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3724202/ 
  11. https://onlinelibrary.wiley.com/doi/full/10.1111/andr.12389 
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6993171/ 
  13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6030011/