Fertility experts have known for some time that female age has a pretty dramatic effect
on fertility and fertility treatments. Older women have a harder time becoming
pregnant and have lower success rates with fertility treatments like IVF. The effect
of male age however has not been studied as well, especially in IVF cycles. A new study
may help decide whether older men also have an impact on IVF success rate. Stay tuned.
Part of the problem with trying to study the impact of male age on something like IVF success
is the difficulty in separating the impact of the sperm from the egg. Older males tend to have older
female partners. If IVF pregnancy rates are lower, it is difficult to know whether that decline
is due to declining egg quality alone, sperm quality or some combination of the two.
For example, a recent study looked at 77,000 cycles from the US IVF registry. They found
lower pregnancy rates when the male partners were 45 or over. But when they looked only
at cycles in which the females were young, under 35, there was no difference in the pregnancy rate
One way to try to get around this problem is to look at the success rates in egg donor cycles. Egg
donors are specifically chosen to be young. Egg donation pregnancy rates are generally very high
so if the pregnancy rate is reduced and the male partner is of more advanced age,
that could be a clue that the male age is responsible. A recent review of twelve
studies however failed to find an impact of male age on the success rate of donor egg IVF cycles.
The problem is that even with egg donors, there may still be too much variation from
donor to donor and this might be obscuring the impact of male age.
Researchers from Cornell University devised a clever way to get around this problem.
They looked at donor egg cycles in which the eggs from each egg donor were split and given to
two different recipient couples. Then they looked at those cycles in which the male age
in one recipient couple was under 45 years old and the male age in the other recipient couples was
45 or older. Since the eggs were from the same donor and retrieved at the same time,
any differences between the recipient couples could only be due to the sperm.
What were the results? There were 144 recipient couples. 77 couples had younger male partners
and 77 had older male partners. The average age of the males in the younger group was
41. They ranged from 38 years old to 43. The average age of the males in the older group was 48
ranging from age 46 to age 51. Some of the recipient couples had transfer of one embryo
and some had two embryos. The proportion was similar in the older and younger groups
The likelihood of a positive blood test for pregnancy was about the same in both groups.
When researchers looked at how likely it was that a pregnancy would reach the point at which
it could be seen on ultrasound, they found a pregnancy rate in the younger group was 81%
compared to 69% in the older group. This seems like it is better, but statistical
analysis found that these results were likely just due to chance and not because of any true
difference in the groups. The same thing happened when they looked at the percentage of live births
Our InfertilityTV Bottom line is this. Researchers have so far not been able
to prove that older males cause lower IVF pregnancy rates in their partners.
That doesn't mean it is impossible, only that we have not been able to prove it with good science.
It may be that there is a small difference that requires a much larger study to find.
Or maybe we need to look at couples with much older male partners. Until we can prove it,
we would not recommend considering male age as a factor determining IVF success rates