A new study suggests men have a biological clock that starts ticking around the age of 35.

The French study, which involved more than 12,000 couples undergoing fertility treatments, found that miscarriage rates started to climb once men reached their mid-30s.

The miscarriage rate for women with male partners aged 30 to 34 was 16.7 per cent. It jumped to 19.5 per cent for male partners aged 35 to 39 and 32.5 per cent for men over 40 to 45.

Dr. Tom Hannam, a fertility expert, said the so-called "biological clock" has always been a big deal for women.

"It'll be interesting to see as this information comes out if men start to feel the same sorts of pressures," he told CTV's Canada AM on Tuesday.

Still, Hannam said most men will be fine into their early 40s.

"(A man) would start to really notice a difference if he did a sperm count when he was a younger man versus in his late-40s," he said.

Hannam said the study is helpful for couples because it's often solely women who take on all the responsibility when there is trouble conceiving a child or when there's a miscarriage.

"This is just another reminder that it's the couple that's going through this together," said Hannam.

Dr. Stephanie Belloc, who led the research team for the study, said the findings show older couples should consider IVF (in vitro fertilization) at an early stage if they can't conceive naturally.

"We believe that the use of IVF should be suggested to infertile patients where either party is over 35 years of age," said Belloc, according to a report in The Times Online.

Belloc discussed her findings at the annual European Society of Human Reproduction and Embryology meeting in Barcelona on Monday.

The report is due to be published in the journal RBM Online.