Drugs (both legal and illegal), alcohol and tobacco can all reduce the health of your sperm and the likelihood that you and your partner will conceive. Avoiding these substances so that the body can detox when preparing for pregnancy, will help ensure the sperm you produce are optimally healthy. This will increase your chances of conception, and ensure that the pregnancy gets off to the healthiest start possible.
Smoking and sperm
Smoking reduces your fertility by affecting the concentration, motility and shape of your sperm. On average, men who smoke have a lower concentration of sperm in their semen. In addition their semen contains a higher concentration of sperm which are immotile (unable to swim) and abnormally shaped.
Because of their shape, these sperm may be immotile, but even if they can swim properly, they will have a harder time trying to penetrate and fertilise an egg, compared to normally shaped sperm. There is also some evidence that smoking reduces the quality of DNA in a man’s sperm, and that this may in turn make the children of fathers who smoke around the time of conception, more susceptible to some conditions like childhood cancer.
Alcohol and sperm
Alcohol affects the health of dad’s sperm by influencing the function of the cells in the testes which produce testosterone (Leydig cells) and those which are regulated by testosterone to produce sperm (Sertolli cells).
It also affects the functions of the hypothalamus, a gland in the brain which produces other hormones involved in sperm production, luteinising hormone and follicle stimulating hormone.
While alcohol is known to affect hormone production in men, little is known about the ways in which altered hormones affect the health of men’s sperm in the short term. In the long term, heavy drinking has been shown to reduce fertility in men.
Those who drink excessively ejaculate a smaller quantity of semen each time, and their semen contains a lower number of sperm compared to men who do not drink heavily. The sperm of heavy drinkers are also less motile. It is therefore recommended that men limit their alcohol consumption whilst trying to conceive.
Recreational drugs have an adverse effect on a man’s fertility and should be avoided in general but particularly whilst you are trying to conceive. Marijuana and cocaine impair sperm production by affecting the cells in the testes which produce sperm.
Heavy marijuana users have lower concentrations of sperm, which may take 2-3 months to recover when the man stops using marijuana. Marijuana also reduces testosterone levels which can impair sperm production.
Similarly, cocaine use lowers the concentration of sperm in the semen. It has also been associated with the production of immotile and abnormally shaped sperm. Cocaine use may also increase the likelihood of erectile dysfunction (the inability to achieve and maintain an erection) which indirectly affects fertility.
Opiate drugs such as heroin may also reduce fertility because they have hormone altering effects and decrease libido.
Performance enhancing drugs
Performance enhancing drugs such as anabolic steroids impair fertility because they alter hormone production and reduce libido. The effects are reversible, but if you’ve been using steroids, it may take 6-12 months before your sperm gets back to normal.
A number of medications can affect male fertility. If you use medicines and are trying to conceive, talk to your doctor about whether or not any of your medicines may be affecting your fertility. In most cases an alternative medicine which does not impair fertility can be prescribed. Some common medications which reduce fertility include those for treating:
- Hypertension: which may either alter your hormone production or reduce your libido or erectile function;
- Psychological conditions: many of which cause erectile dysfunction (inability to achieve and maintain an erection) and reduce libido, as well as altering hormone production in your body;
- Hormones: which alter your hormone profile and may also cause reduced libido and/or erectile dysfunction;
- Antibiotics: which can inhibit sperm production. Some antibiotics may alter hormone production;
- Opiate pain relievers: reduce libido and cause erectile dysfunction because they reduce testosterone levels in your body.
The effect of most medicines is reversible, that is, fertility will return once you stop using the medicine. However, you should never stop medication suddenly or change your dosage without your doctor’s advice.
Chemotherapy medicines have an irreversible effect on male sperm production. Men in their reproductive years who require chemotherapy have the option of cryopreserving (freezing) sperm so that they can conceive children using assisted reproductive techniques such as in vitro fertilisation (IVF) and intrauterine insemination (IUI).