So you want to be a dad? Well guys, that’s another great reason to kick that smoking habit once and for all. With a lethal mix of over 7000 chemicals in tobacco smoke, it shouldn’t come as a surprise that smoking can seriously affect your little swimmers. In fact, research suggests that smoking can reduce a man’s fertility by as much as 30%! Read on to find out how smoking can decrease your odds of becoming a father.

The man’s role in natural conception

Sperm meets egg and ta-da! there’s a baby on the way. Putting it like this can make fertilisation look like a fairly easy process but it’s certainly more complex. For natural conception to occur, the man’s body must be able to:

  • Maintain an erection;
  • Produce and ejaculate sufficient, healthy and well-formed sperm;
  • Produce fast swimmers that can move in the right direction.

As you can imagine, anything that disrupts one or more of these key events can reduce your chances of pregnancy. And guess what, smoking messes with all three!

Here’s why smoking spells trouble for your fertility

Erectile dysfunction

It seems that smoking could make it more difficult for a man to maintain an erection for various reasons.

  • Scientists have associated the chemicals in the smoke to a higher likelihood of atherosclerosis, build-up of plaque in the arteries. Since this plaque hinders blood flow throughout the body, circulatory issues down there could make it harder for the big guy to stand up.
  • Smoking does not only damage blood vessels but it also causes harm the penile tissue itself. Consequences: as the penis loses its elasticity, it gradually becomes less able to stretch.

Statistics don’t lie:

Researchers who looked at several studies involving a total of over 28,800 participants reported that compared to never-smokers, the risk of erectile dysfunction increased by 51% for current smokers and 20% for ex-smokers.

And the more you smoke, the more vulnerable you may be to erectile dysfunction. Scientists who analysed data on almost 4800 men found that men who smoked over 20 cigarettes per day had a whopping 60% higher risk of erectile dysfunction compared to non-smokers.

Poor semen quality

Several studies comparing semen quality between smokers and non-smokers found that male smokers are more likely to show the following characteristics:

  • Low sperm count – The sperm count refers to the number of sperm in your semen. Your sperm count would be considered lower than normal if your semen contains fewer than 15 million sperm per millilitre.Does that sound like a lot? If yes, then you may be surprised to know that healthy ejaculate is usually composed of around 200 million sperm mixed with semen. However, in most men with a normal sperm count only around 400 sperm survive after ejaculation. And only 10% of these (about 40 sperm) can actually come close to the egg although only one lucky fellow will be able to penetrate it.
  • Abnormal sperm shape – Healthy sperm has a round head and a long tail which help this little champion swim and ultimately penetrate the egg to fertilise it. Sperm that has more than one head or tail; an abnormal middle-piece; or an abnormally shaped head or short tail has been linked to fertility issues.
  • Suboptimal sperm motility – Sperm motility refers to the swimming ‘skills’ of the sperm. If it cannot swim properly, the sperm won’t be able to come close enough to the egg let alone ‘win the race’ and fertilise the egg.

Statistics don’t lie:

Researchers investigating differences in semen quality between smokers and non-smokers found that smokers had a 15.3% decrease in sperm density, a 17.5 to 24% lower sperm count and 16.6% fewer motile sperm.

Again, the more puffs you take, the more your semen quality is likely to be affected: a study involving over 2500 men showed that heavy smokers had a 29% lower sperm count and a 19% lower sperm density compared to non-smokers. Heavy smoking was defined as smoking more than 20 cigarettes per day.

Overview: what smoking does to your sperm

Because of their fragile structure and high levels of lipids in their cell membranes, spermatozoa are very sensitive to oxidative stress caused by the reactive oxygen species (ROS), also known as free radicals, found in cigarette smoke.

Scientists have discovered that these ROS can damage and kill sperm cells by:

  • Triggering a chain of chemical reactions that cause the fatty membrane of sperm cells to break down. Without this protective and highly specific barrier, the spermatozoa lose their flexibility, motility and fertilising potential.
  • Inducing DNA damage such as deletion and mutation of genes in the spermatozoa’s nucleus. This can lead to abnormal changes in the sperm’s shape – some can develop an additional head whilst others may have flat heads and short tails.
  • Decreasing levels of antioxidants in the semen – these help protect the delicate sperm.

What about marijuana?

You’re not off the hook either.

A study presented at the 2003 annual meeting of the American Society of Reproductive Medicine in San Antonio, Texas, reveals that cannabis use can impair male fertility. The researchers speculate that THC, the active ingredient in cannabis, may disturb the sperm’s timing.

“The sperm from marijuana smokers were moving too fast, too early. The timing was all wrong. These sperm will experience burn-out before they reach the egg and would not be capable of fertilisation,” reported study lead author Lani Burkman. The scientists also found that the pot smokers had a smaller semen volume and fewer sperm compared to those who didn’t smoke. These observations have been previously linked to infertility in other studies.

In a lab study, scientists at Aberdeen University discovered that marijuana interferes with testosterone, the reproductive hormone that plays a crucial role in the production of sperm.

“[Cannabis] appears to affect the way the testes make and release testosterone, and has an impact on the way the brain regulates production of the hormone,” explained Dr Fowler, the study’s lead author.

Things you can do to boost your fertility

Stop smoking!

Okay, that’s kind of stating the obvious but here are some encouraging research findings:

  • A small study showed that men who stopped smoking experienced a 50 to 80% increase in sperm count indicating that the damage smoking does to male fertility may be reversible.
  • Another study found that men who managed to quit smoking and stop nicotine patches had thicker and firmer erections compared to those were still smoking and using the patches. And get that, the men who remained nicotine-free reached maximal arousal five times faster than those who relapsed. (Not to worry, these men did not climax faster.)
  • Men who successfully stopped smoking had a 75% remission rate of erectile dysfunction.

Seek treatment

We know that albeit being a simple test, semen analysis can be very stressful and perhaps embarrassing for some men. But the test remains the first step to take when a couple is having trouble conceiving.

Nourish your little guys

Check out our articles on fertility diet for him and factors that affect male fertility.

Maintain a healthy weight

More information about the link between weight and male fertility.

Make heart-healthy changes

Researchers found that, compared to men who didn’t try to lower their risk factors for heart disease, those who did were 2.5 times more likely to experience an enhanced sexual function after as little as six weeks. This analysis included six clinical trials involving over 700 men from four countries.

Wondering how these men improved their heart health? They simply exercised more, ate healthier and controlled their blood pressure and cholesterol levels.

If you need support, do not hesitate to contact the NHS Smoking Helpline.


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