The chance of a couple having a baby falls by a third when a potential father is older than 50, according to a new study, revealing that men do have a biological clock.
Reviewing data gathered from 4,300 Britons undergoing fertility treatment allowed a team from the Centre for Reproductive and Genetic Health in London to pin down the start of male biological clock, when fertility sharply declines.
They found the probability of a live birth for men over the age of 50 undergoing fertility treatment was 33 per cent lower than for younger men.
Lead author Dr Guy Morris said newspaper stories of celebrities fathering children into their 60s has perpetuated a myth that ‘male fertility lasts for ever.’
In fact, he says this isn’t true and there should be public health messages that urge men not to delay fatherhood if they decide they want to have children.
The chance of a couple having a baby falls by a third when a potential father is older than 50, according to a new study, revealing that men do have a biological clock. Stock image
Delayed parenthood around the world is becoming more common for both men and women, according to the team behind the number study.
The age of first-time mothers has increased steadily in recent decades – a trend matched by older fathers, and of babies born in 2016 in England and Wales, 15 per cent had a father aged over the age of 40.
The phenomenon has been has been linked to increasing rates of premature births and seizures in new-borns – and gestational diabetes in mothers.
Dr Morris said: ‘Our study showed live birth and clinical pregnancy are negatively affected by paternal age over 50 years.’
The findings, published in the journal Acta Obstetricia et Gynecologica Scandinavica, is based on 4,833 IVF/ICSI cycles performed at a London clinic.
The drop in live birth rates was independent of female age, the team discovered.
They said this particular cohort study was useful as it contained a large number of men over the age of 50 and with details on all causes of infertility.
‘This ensures our findings are generalisable to the majority of couples attending for sub-fertility assessment and treatment,’ said Dr Morris.
The UK team also took into account quality of semen and the method of fertilisation, and accounted for other confounding variables such as maternal age.
He added: ‘Irrespective of the cause of infertility, increased male age is associated with a reduced live birth,’ but doesn’t increase miscarriage rates.
Reviewing data gathered from 4,300 Britons undergoing fertility treatment allowed a team from the Centre for Reproductive and Genetic Health in London to pin down the start of male biological clock, when fertility sharply declines. Stock image
‘Further work on the possible mechanisms of this effect and whether there are enhanced sperm selection techniques that can mitigate it, is required.’
The study did not take into account lifestyle factors such as weight, smoking or drinking, which could also influence outcomes independently of age.
But there were signs sperm quality was worse in the older men, with only four in ten of those over 51 in the cohort having a sperm count within the healthy range compared to six in ten for the younger members of the cohort.
A 2017 study of 19,000 IVF treatment cycles in the US found women under 30 with a male partner aged 30 to 35 had a 73 per cent chance of a live birth.
But that impressive success rate plunged to 46 per cent when the man was aged 40 to 42, it didn’t explore the impact in men over the age of 50.
The findings have been published in the journal Acta Obstetricia et Gynecologica Scandinavica.
THE CAUSES OF MALE INFERTILITY
The most common cause of infertility in men is poor-quality semen, the fluid containing sperm that’s ejaculated during sex.
Possible reasons for abnormal semen include:
a lack of sperm – you may have a very low sperm count or no sperm at allsperm that aren’t moving properly – this will make it harder for sperm to swim to the eggabnormal sperm – sperm can sometimes be an abnormal shape, making it harder for them to move and fertilise an egg
Many cases of abnormal semen are unexplained.
There’s a link between increased temperature of the scrotum and reduced semen quality, but it’s uncertain whether wearing loose-fitting underwear improves fertility.
Testicles
The testicles produce and store sperm. If they’re damaged, it can seriously affect the quality of your semen.
This can happen as a result of:
an infection of your testiclestesticular cancertesticular surgerya problem with your testicles you were born with (a congenital defect)when one or both testicles hasn’t descended into the scrotum, the loose sac of skin that contains your testicles (undescended testicles)injury to your testicles
Sterilisation
Some men choose to have a vasectomy if they don’t want children or any more children.
It involves cutting and sealing off the tubes that carry sperm out of your testicles (the vas deferens) so your semen will no longer contain any sperm.
A vasectomy can be reversed, but reversals aren’t usually successful.
Hypogonadism
Hypogonadism is an abnormally low level of testosterone, the male sex hormone involved in making sperm.
It could be caused by a tumour, taking illegal drugs, or Klinefelter syndrome, a rare syndrome where a man is born with an extra female chromosome.
Medicines and drugs
Certain types of medicines can sometimes cause infertility problems.
These medicines are listed below:
sulfasalazine – an anti-inflammatory medicine used to treat conditions such as Crohn’s disease and rheumatoid arthritis; sulfasalazine can decrease the number of sperm, but its effects are temporary and your sperm count should return to normal when you stop taking itanabolic steroids – are often used illegally to build muscle and improve athletic performance; long-term abuse of anabolic steroids can reduce sperm count and sperm mobilitychemotherapy – medicines used in chemotherapy can sometimes severely reduce sperm productionherbal remedies – some herbal remedies, such as root extracts of the Chinese herb Tripterygium wilfordii, can affect the production of sperm or reduce the size of your testiclesillegal drugs, such as marijuana and cocaine, can also affect semen quality.
Source: NHS
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