New research by Australian fertility experts has shown that IVF success rates drop as men age, debunking the myth that only women experience declining fertility as they get older.

The new study by researchers from Monash University and Monash IVF[1] found that in couples with unexplained infertility, increasing male age is associated with falling rates of live birth, clinical pregnancy and embryo implantation, while the miscarriage rates increase.

The male study participants’ chance of live birth decreased by 4.1 per cent with each year of increased age, with outcomes significantly worse for men in their fifties.

In the study, the men’s chance of conceiving halved from the age of 50, compared to those under 40.

Lead author and PhD candidate Fabrizzio Horta, from the Monash University School of Clinical Sciences, said that while previous studies have explored the effect of male age on fertility, few have controlled the impact of female age and confounding factors, focused solely on the role of male age in infertile couples.

“We found that male age always has a negative effect on fertility, even if men partner with younger women,” said Mr Horta, who also works as a clinical embryologist at Monash IVF.

“It’s well known that women’s fertility declines as they age, but there has been less information about the role that male age plays when a couple is struggling to fall pregnant.

“By controlling the impact of female age and confounding factors, we were able to look specifically at the effects of male ageing for couples undergoing IVF and show that it has a significant impact on conception.”

In the retrospective cohort study, published in the Journal Human Reproduction, researchers analysed 2425 IVF or ICSI cycles of 1506 Monash IVF patients with unexplained infertility between 1992 and 2017. Couples with diagnosed female-factor infertility were excluded from the subset.

Co-author of the study Beverley Vollenhoven, a Monash IVF Fertility Specialist and Professor of Obstetrics and Gynaecology at Monash University, said the study highlights the importance of educating men about their fertility at a time when more people are delaying parenthood.
In 2018 the median age for fathers reached an all-time high of 33.5, up from 33.1 in 2008, according to ABS data.

“The number of men over the age of 35 having children has increased significantly,” Professor Vollenhoven said.

“Stories of ageing celebrities fathering children into their senior years can give false hope, when in reality we know that men are not immune to the biological effects of ageing.

“Age related fertility decline for men is more subtle than for women, but it does happen.

“Male age has a negative effect on sperm count and quality. As men age, their sperm is more susceptible to DNA damage that can increase the time it takes to fall pregnant or result in miscarriage.”

Professor Vollenhoven said that the study emphasises the need for clinicians and couples to consider both male and female age in fertility planning and assessment.

“For men, fertility declines each year they get older and is significantly worse by their fifties,” Professor Vollenhoven said. 

“For women, fertility decreases significantly from their mid-thirties because of reduced egg quality.

“It’s vital that everyone is educated about the impact that age has on their fertility so they can make informed lifestyle choices.”