As men we’re often prone to thinking that the seconds of the ‘biological clock’ tick mercilessly away for the fairer sex alone. Whilst women are bombarded with health advice warning of the potential fertility issues and pregnancy complications associated with having kids later in life, we men are blessed with a certain smug complacency that leads us to believe that we can happily father children up until the day we die. And of course, being involved in the act of procreation at the moment of our demise is probably how most of us would want to go.
Unfortunately however, new research just published in the medical journal Fertility and Sterility comes as a stark reminder that trying to conceive a child that you’d probably be too old to cradle on the day of his/her birth could be more of a challenge than you’d bargained for.
The research, conducted by fertility specialists at Shanghai Institute of Planned Parenthood Research analysed semen samples taken from approximately 1000 Chinese men aged between 20 – 60. Their surprising results indicate that sperm health starts to gradually deteriorate after the age of 30; and that by the age of 35 the cumulative effects of this decline can have a pronounced impact on sperm quality.
The research published in the medical journal Fertility and Sterility found that whilst sperm count and semen volume remained relatively unchanged regardless of age, three distinct physiological changes gradually occurred after the age of thirty which most fertility specialists would agree could ultimately impede male fertility.
Reduced Sperm Motility & Increased Abnormalities
Specifically, the researchers found that abnormalities in sperm morphology – i.e. the shape and size of sperm – steadily rise over the years. Overall they noted a 16 percent higher abnormality level in sperm samples taken from test subjects in their 50’s in comparison to their younger counterparts still in their 20’s.
Whilst sperm abnormalities aren’t uncommon even in younger men, experts do warn that such deformities (such as sperm with misshapen or oversized heads and/or doubled or crooked tails) can prevent sperm from effectively navigating their way to, and then penetrating an egg. Increased numbers of abnormal sperm may therefore be a contributory factor to male fertility problems.
Possibly linked to the above finding, the researchers also found that from the age of 30 onwards, sperm motility – i.e. the number of sperm with the capacity to move or ‘swim’ efficiently – fell by around 1 percent a year.
And to compound these potential male fertility problems, the scientists also found that the numbers of living sperm in the donor samples also declined with age. Those in their 20’s had an average ‘live’ sperm count of 73 percent, whereas the figure fell to around 60 percent for men in their 50’s and 60’s.
So in other words, according to this new research, by the time the average man hits his fifties, almost half the sperm he produces are stone cold dead before they even get to do the crawl.
But whilst many men in their fifties would probably gracefully accept such a decline in fertility to be an inevitable part of the aging process, the fact that these combined negative effects are likely to present a marked deterioration in overall sperm health as early as one’s mid-thirties may well come as something of a shock.
The good news however, is that the study stopped short of concluding a direct link between this gradual decline in sperm health and any actual risk of infertility later in life.
However, the bad news is that previous studies have explicitly made that connection.
Age & Male Infertility: The French Connection…
In a study published in the same journal in 2006, researchers from the French National Institute for Demographic Studies examined the success rates of IVF treatments in 1938 couples, all of whom were receiving treatment for female related infertility problems. Although the male partners were all fertile, the researchers nevertheless noted a distinct inverse correlation between the age of the male partner and the likelihood of a successful pregnancy.
In cases where the male partner was over 40 years of age, couples experienced significantly reduced IVF success rates. For woman in their late 30’s, pregnancy success rates fell by 50 percent, whilst even women in their 20’s had a 25 percent reduced likelihood of conceiving if their partner was over 40 years of age.
In summary, the authors of the study warned that in light of the growing trend to postpone having children, couples should be informed of the increased infertility risks associated with a paternal age over 40.
Whilst the above French study is one of the few to have expressly warned of a direct link between advancing years and reduced male fertility, as with the new Chinese research, several others have intimated the connection by showing a physiological link between deteriorating sperm health and older age.
Further Corroboratory Studies…
In a study published in the male infertility journal Andrologia in 2007, fertility specialists from Soroka University Medical Center, Israel, correlated the relationship between sperm health and age through the analysis of 6022 sperm samples.
In line with the latest Chinese findings, this 2007 study also observed a significant decline in sperm motility as the years drew on. Men under the age of 25 were found to have the greatest number of ‘good swimmers’ in each semen sample (44.39 +/- 20.69%), whilst those of 55 years of age and over saw their sperm motility numbers plummet to 24.76 +/- 18.27% – much lower even than the levels recorded in the new study.
In fact, in percentage terms the researchers recorded a drop in sperm motility of 54 percent between men in their mid-thirties and those in their mid-fifties.
One good piece of news however, is that the Soroka University data seems to suggest that the negative effects of these ‘sperm health’ issues only really manifest themselves in later middle age. In fact, the Israeli scientists noted that semen volumes per ejaculate actually peaked between the ages of 30 and 35 (at a mean average of 3.51 ml per ejaculate); and this finding along with the analysis of a multitude of other factors led them to conclude that ‘top sperm parameters’ occurred between the ages of 30 – 35.
So if you’re hurdling towards your mid-thirties and you’re still putting off perpetuating the gene pool, this study at least suggests that your little guys should still be up to swimming the channel for a few more years to come.
The Genetic Factor…
But in addition to sperm count, motility and morphology, experts advise that older age is also associated with an accumulation of sperm DNA fragmentation – which can again, take its toll on male reproductive health.
Scientists from Lawrence Livermore National Laboratory for example, reported in 2006 that sperm samples taken from 97 men between the ages of 22 and 80 showed increasing levels of gene mutations and chromosomal abnormalities as the years rolled by.
They concluded that this gradual build-up of genetic damage might not only be associated with a corresponding decrease in male fertility, but that it might also contribute to increased rates of both miscarriage and genetic birth defects – in particular dwarfism.
So are we all leaving parenthood too late?
With all these statistics regarding the impact of age on male fertility flying about, you might be excused for thinking that any man past the age of 30 should forget the kids and go straight for the pipe and slippers.
But the fact is statistics show that almost two thirds of children are in fact fathered by men in their thirties. And what’s more, the number of older fathers is on the increase.
The US National Center for Health Statistics in 2004 for example, recorded an 18 percent increase in the number of fathers aged between 40 and 44 in comparison to the previous decade. Across the pond in the UK, the Office for National Statistics now reports that 10 percent of all new-borns are fathered by men in their 40′s, whilst 1 in 100 has a father over the age of 50.
And of course, there may well be advantages to postponing fatherhood – from a greater likelihood of being a father through choice, through to greater financial security – all of which undoubtedly have a positive bearing on children.
But what is undoubtedly true is that there’s a subtle balancing act to be played between the positives and negatives of later fatherhood.
Although men are fortunate enough not to experience the same abrupt cut off point to their fertility as experienced by women through the menopause, we nevertheless need to take into account that our fertility levels will gradually decline as the years pass us by – and the effects may have an impact sooner than we’d think (or like).
The message from the various studies seems clear…the subtle deterioration to the quality of our sperm may start to gradually hamper our ability to fertilize from our mid-thirties, whilst the cumulative effects of reduced sperm count, motility as well as increased genetic abnormalities may in later years also lead to increased rates of miscarriage and birth deformities. These are factors that couples should add to the equation when it comes to planning a family, instead of just assuming (as is conventionally the case) that paternal age has no relevance.
But of course, there will always be those men who refuse to bow to convention.
Charlie Chaplin for example, fathered his twelfth child at the age of 73, whilst actor Anthony Quinn left it until he was 81. Pulitzer Prize winning author Saul Bellow trumped them both in 1999 when he fathered his 4th child aged 83.
And whilst you might think that celebrity status might ease the strain and increase the accessibility of late fatherhood, have a thought for the world’s oldest (now deceased) new father. That accolade went to an Australian miner by the name of Les Colley who in 1992 fathered a new son to his new Fijian wife at the age of 93.
In many ways, his appearance probably resembled that of his new born child and his wife probably changed their nappies at the same time to kill two birds with one stone. But without doubt…there was certainly life left in that old dog long past the point when most of us would have given up the ghost.
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