Men have a biological clock too, fertility drops after age 50

LONDON — Men also appear to have a biological clock when it comes to fathering a child, a new study reveals. A team from the Centre for Reproductive and Genetic Health in London says a couple’s chances of having a baby falls the older the potential dad gets.

Although many celebrities have become fathers again later in life, like music legend Mick Jagger, scientists say men should not wait too long to start a family – just like women.

The study of almost 4,300 adults undergoing fertility treatment discovered the probability of a live birth is 33 percent lower if the father is over 50 years-old. Lead author Dr. Guy Morris says stories of celebrities fathering children into their 60s have contributed to the myth that “male fertility lasts for ever.”

“Paternal age over 50 significantly affects the chance of achieving a live birth following assisted reproductive technology,” researchers write in a media release. “There should be a public health message for men to not delay fatherhood.”

Waiting to have kids is a worrying trend

The findings in the journal Acta Obstetricia et Gynecologica Scandinavica come from a review of 4,833 IVF/ICSI cycles performed at a London clinic.

Delayed parenthood around the world is becoming more common for both men and women. The age of first-time mothers has increased steadily in recent decades, a trend matched by older fathers. The phenomenon has been linked to increasing rates of premature births and seizures in newborns and gestational diabetes in mothers.

“Our study showed live birth and clinical pregnancy are negatively affected by paternal age over 50 years,” says Dr. Morris in a statement to SWNS.

The report included 200 men, making it one of the largest to assess the effect of increased male age on assisted reproductive technology (ART) outcomes.

“This effect was independent of female age. A strength of this cohort study is that it includes a large number of men over the age of 50 years, the second largest cohort in the literature, and includes all causes of infertility,” Dr. Morris tells SWNS. “This ensures our findings are generalizable to the majority of couples attending for sub-fertility assessment and treatment.”

The U.K. team also took into account the quality of semen and the method of fertilization.

“Our analysis attempted to account for the major confounding variable, maternal age, that may have influenced outcome,” Dr. Morris explains. “Irrespective of the cause of infertility, increased male age is associated with a reduced live birth.”

Will older fathers lead to more miscarriages?

Despite age being a factor in fertility, the team discovered it does not appear to increase the rates of miscarriage.

“Further work on the possible mechanisms of this effect and whether there are enhanced sperm selection techniques that can mitigate it, is required,” Dr. Morris concludes.

The study did not take into account lifestyle factors such as weight, smoking or drinking, which could also influence outcomes independently of age. However, there were signs sperm quality was worse in the older men.

Around four in 10 of those over 50 years-old had sperm count and motility measures within the healthy range defined by the World Health Organization, compared with six in 10 younger participants. A 2017 study of 19,000 IVF treatment cycles in the U.S. found women under 30 with a male partner between 30 and 35 have a 73-percent chance of a live birth. That success rate plunges to 46 percent when the man is between 40 and 42.

South West News Service writer Mark Waghorn contributed to this report.