Study suggests benefits of elective sperm freezing for men concerned about declining fertility
Growing numbers of Australian women are taking up the option of elective egg freezing to preserve their reproductive capacity if their fertility is threatened by advancing age.
However, a senior researcher in assisted reproduction says the freezing option should also be considered by men, as she will present evidence that their reproductive capacity reduces with age.
Franca Agresta, the Clinical Research Manager for Melbourne IVF, member of Virtus Health will present the case for elective sperm freezing at the annual scientific meeting of the Fertility Society of Australia (FSA) in Hobart this week.
She will outline research jointly conducted by Melbourne IVF, the Royal Women’s Hospital and the University of Melbourne that explored the effect of paternal age on pregnancy outcomes in assisted reproductive technology.
The research revealed significantly lower clinical pregnancy rates from men aged above 40 years whose female partners were aged less than 35 years.
Ms Agresta said the outcome could help couples to manage their pregnancy expectations when paternal age is a consideration. It also reaffirms that an upper age limit for sperm donors may be warranted.
“It has been firmly established that advanced maternal age beyond the benchmark of 35 years is linked to reduced fertility in women, and that is why globally there is a growing trend towards elective egg freezing to preserve fertility until they are ready to start a family,” she said.
“But the impact of paternal age, especially in assisted reproductive technology such as IVF, has received relatively little attention. This is evidenced by a lack of global consensus among professional bodies in assisted reproductive medicine about upper sperm donor age limits.
“The clinical pregnancy rate among women aged under 35 and men under 40, whose average age was 33, was 39 per cent. However, among women under 35 whose male partners were above 40, and whose average age was 44, the clinical pregnancy rate reduced to 26 per cent,” Ms Agresta said.
The research to be presented at the FSA conference in Hobart involved retrospective analysis of 1,403 IVF single embryo transfer cycles performed at Melbourne IVF between January 2014 and January 2019.
Ms Agresta said: “We only looked at cycles in which the female age was less than 35 years to eliminate the negative effects of advanced maternal age attributed to egg quality, and restricted the ovarian stimulation cycles to two to control for an aetiology that may be attributed to female factor infertility.
“It clearly showed that increased paternal age negatively influences clinical pregnancy rates.
“The reasons for reduced male fertility include impaired semen parameters such as reduced sperm counts and motility. But the causes in older men are not fully understood, and may involve DNA damage either from oxidative stress or epigenetic modifications.
“Like eggs, sperm can be cryopreserved for many years and result in viable pregnancies, and it is a relatively simple procedure,” Ms Agresta said.
“As more and more couples accessing fertility treatment are now mutually of an advanced age, there is a clear message about the possible benefits of elective sperm freezing for men who are concerned about declining fertility, and for women partnered by older men.
“It certainly provides an opportunity to further counsel couples about the impact of delayed attempts at parenthood and of managing their expectations of how outcomes from assisted reproductive treatment may be influenced by paternal as well as maternal age,” Ms Agresta said.
Further research is now required to understand the aging effects on sperm quality and whether these can be circumvented.