29th Aug, 2017
Environmental factors such as air- borne pollutants and pesticides in our foods are leading to a decline in the quality and quantity of male sperm, says Lorraine Courtney
Men’s sperm counts have fallen by almost 60% since the 1970s, according to major new research which cautions that our modern world may be prompting a male fertility crisis. Over the past few years, various studies have pointed to declining sperm quality and quantity. This latest research, and the first systematic review of trends, looked at 180 studies over four decades. It concluded that total sperm counts in Western countries have fallen by 59% since 1973, with a 52% fall in sperm concentration, or the concentration of sperm in a man’s ejaculate.
“Decreasing sperm count has been of great concern since it was first reported 25 years ago,” says Dr Shanna H Swan, a professor in the Department of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai, New York and study leader.
“This definitive study shows, for the first time, that this decline is strong and continuing. The fact that the decline is seen in Western countries strongly suggests that chemicals in commerce are playing a causal role in this trend.” The chemicals he refers to range from everyday air pollutants to pesticides or even soap. So should the average man panic?
A first glance at the statistics suggests that we are faring well. Ireland had the highest birth rate among EU countries last year. 2016 saw 63,900 live births recorded according to figures from Eurostat, the EU statistics agency. That’s a super healthy rate of 13.5 births for every 1,000 of the population. Italy was the lowest with just 7.8 births for 1,000 of the population.
However, male infertility is a factor for half of the couples who seek fertility treatment here in Ireland. Azoospermia (absence of spermatozoa in the ejaculate) is a condition present in approximately 1% of males in the general population. Between 10-15% of infertile men who attend assisted reproductive technology clinics here have had a diagnosis of azoospermia. However, approximately 30% of couples present where there is suboptimal sperm count or reduced motility, impacting on the couples’ ability to conceive a child.
Dr Tim Dineen, head of laboratory services at Cork’s Waterstone Clinic, says the study draws attention to a trend that doctors and scientists working in reproductive medicine have been aware of for many years.
“The decline in sperm counts is very gradual and is unlikely to prevent any individual man fathering children naturally in the short term,” says Dr Dineen.
“It is also important to point out that if a man’s sperm count is so low that natural conception is impossible, intracytoplasmic sperm injection (ICSI) treatment is able to compensate for the problem very successfully.”
Treatments, in the form of ICSI, have been very successful in overcoming male subfertility and male infertility. In the Waterstone Clinic, for those couples where the female partner is younger with good ovarian reserve, a live birth rate of at least 50% (first fresh cycle) is expected.
ICSI costs €4,750 including blastocyst and embryoscope incubator culture at the clinic, which offers a range of treatments.
“It is reasonable to assume that environmental factors are to blame but no one knows exactly which factors are involved,” says Dr Dineen. “Research is urgently required to identify the environmental causes; only then can public health initiatives be undertaken in order to address the problem.”
With an eye on the future, Dr Dineen maintains that if the exact cause of the drop in sperm counts is not discovered and corrected soon, the decline will continue and major problems will arise with regard to the ability of men to father children naturally.