Carrying on from the last blog, in which I looked at female infertility, male infertility is also a cause for infertile couples, accounting for approximately half of infertile couples.
Sperm quality/quantity is often the problem in male infertility. However, aging does not play a major role in infertility in men as it does in women, with accounts of men fathering children much later on in life. The risk of congenital abnormalities with increasing parental age is not as well known about as it for women, but the risks are still present.
It has been found that in 19% of couples suffer from a low sperm count or low quality. Once again, there are many factors that can lead to poor sperm, such as excessive weight. Those that are overweight or obese (with a body mass index of 25 or above) are at an increased risk of low sperm count/quality. Studies into the effect of nicotine on both female and male rats with sperm analysis, fertility, litter size and weight being analysed . The results showed a significant decline in sperm motility and number, as well as a reduced libido in the male rats. However, more recent studies have found no difference in sperm quality between smokers and non smokers. The BBC article, which can be found here, http://www.bbc.co.uk/news/health-18407647 indicates no relationship between smoking and infertility, but still advisable not too, with studies having not considered DNA quality or size and shape of the sperm.
Other factors affecting fertility
Smoking and obesity are factors that can be controlled, but some men suffer from disorders that detrimentally effect the testis and sperm production (spermatogenesis).
The sperm found in some men might be perfectly healthy, and instead there is a problem with the release of the sperm, whether this be due to problems with getting an erection, or problems with ejaculating. There may be physiological or psychological reasons for this, and is usually treatable after a visit and treatment options from a doctor.
Previous medical illness may have an effect on fertility. Certain drug treatments or surgery can affect fertility, as well as radiotherapy and chemotherapy. Depending on which drug was given, as well as dose can affect the risk. Sperm can be preserved before these treatments in order for semen to be available later on if the man wishes to have a child.
Bacterial infections can also cause infertility. The scarring caused by the infection, and the possibility of the tubes within the epididymis connecting to the vas deferens being blocked can have a detrimental effect. The vas deferens is the transport system for the sperm that are ready to be ejaculated.
IVF can help couples in which the man has an infertility problem, by making the fertilisation of the egg as easy as possible by the sperm, whether this be by directly injecting the sperm into the egg, or allowing natural fertilisation but giving the sperm the best chance it can get at reaching the egg through use of a catheter.
 Oyeyipo I, Yinusa R, Emikpe B and Bolarinwa A (2011), Effects of Nicotine on Sperm Characteristics and Fertility Profile in Adult Male Rats: A Possible, Journal of Reproduction & Infertility, 12(3):48