|
 Enormous advances in treating infertility in recent decades have
helped couples conceive longed-for offspring they previously would
not have had.
Yet this progress has also been a work-around for a major part of
the problem: Sperm counts are falling drastically worldwide - and
have been doing so for decades – and scientists say their honest
answer to why is: “We don’t know”.
Infertility is a significant global health problem, with specialists
estimating that as many as one in six couples worldwide are
affected. In more than half of those cases, experts say, the
underlying problem is in the male.
Most of the focus of infertility research has been on women,
however: on what can reduce their fertility and on how that can be
averted, compensated for or corrected with treatment. While this
approach has produced results - and babies - it has also left male
infertility scientifically sidelined.
Treatments such as in-vitro fertilization (IVF) and intracytoplasmic
sperm injection (ICSI), where the sperm is placed into the egg
rather than next to it, bypass the male problem rather than treating
it, said Richard Sharpe, professor at the University of Edinburgh's
center for reproductive health.
"The treatments - some of them quite invasive - are to the female
partner. So the female is having to bear the burden of the male's
sub-fertility ...(And at the same time), we have a very crude
snapshot of what is going on in the male."
We know that sperm counts are dependent on high levels of
testosterone, and there is some knowledge of links between sperm
count and infertility, experts say. But beyond these basics, sperm's
intricacies remain largely undiscovered.
"Without understanding the biology of how normal sperm work, we
can't possibly understand how they don't work, or how to correct the
problem," Sarah Martins Da Silva, a reproductive medicine specialist
at the University of Dundee told a London briefing this week.
Sperm counts in men from America, Europe, Australia and New Zealand
have dropped by more than 50 percent in less than 40 years,
according to pooled research published last year, described by one
of its authors as an "urgent wake-up call" for further
investigation.
STILL IN THE 1950s
Experts say that to address the basic unanswered clinical and
scientific questions in andrology - the study of male reproductive
health - would require research ranging from large, ideally
international, epidemiological studies to detailed lab work to
decipher exactly how sperm cells function.
[to top of second column] |
Allan Pacey, a senior lecturer in andrology at Britain's Sheffield
University, said even at a basic level - the diagnosis of a possible
male fertility problem - the science is lagging.
The techniques of sperm analysis - examining ejaculate under a
microscope, counting the sperm, assessing how well they swim, and
seeing what they look like - were invented in the 1950s, he said.
"And we are still doing the same thing now."
So while estimates suggest as many 1 in 20 young men now have sperm
counts low enough to impair fertility, that remains educated
assumption, rather than data from specific studies.
"The quality of evidence we have got in this area falls way behind
that of other branches of medicine," Pacey said.
Attracting funding for fundamental research into possible
environmental impacts on sperm counts - chemical exposure, for
example, or smoking, obesity, or sport and exercise - is tricky,
partly because such studies need vast numbers of people, take many
years and may not give clear answers.
"In the competitive world of grant funding, there is a view that
male infertility is a problem solved," Sharpe said. "We have ICSI.
OK, this doesn’t fix the problem in the affected men, but it treats
the ‘symptoms', and that's good enough.
"So from an urgency and priority perspective, it's easy to downgrade
when compared to cancer, obesity or cardiovascular disease."
Comprehensive European or global data on funding going to male
fertility research are not available, but in Britain, for example,
only around 3.6 percent of the Medical Research Council Populations
and Systems panel budget was provided for male infertility research
from 2014 to 2017.
Pacey told Reuters he has "a filing cabinet full of failed
applications over the years" and Sharpe noted that once research
falls behind, future studies have less to build on.
"If you're not producing sexy research that's going to come up with
a magic bullet, then people are not going to give you the money," he
said.
(Reporting by Kate Kelland, editing by Philippa Fletcher)
[© 2018 Thomson Reuters. All rights
reserved.] Copyright 2018 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
Thompson Reuters is solely responsible for this content.
 |
