Age is unchangeable risk factor of decreasing fertility both in men and women. In the U.S, about almost 15 percent of couples in their reproductive age taking services associated with infertility issue at some point in their lives! In other words, fertility problem has a major public health impact! Men over 30 can successfully father children, though their fertility level is not as well as in the age of younger than 30.
It’s clear that male and female fertilities decrease along with the age. The decreasing of fertility can be noticed more clearly in women over 40. But in men, this occurs slower than in women and there is still no clearly threshold of sperm production in men.
According to a research supported by the Danish Medical Research Council and the National Institute of Child Health & Human Development, female and male fertilities may peak at around 30.
This research found that in women, the decline of fertility may significantly occur in the age of 35 to 40. Women in this category had about 23 percent lower chance of getting conception than women in the age of 20 to 24.
Males showed the same tendency, but the decline occurred smaller than in females because it declined only about 5 percent among men aged 35 to 39.
According to a review of some literatures and studies, ‘Fertility and Sterility Vol-75 2001’ published by Elsevier Science Inc. – seven of ten studies that analyzed the effect of age on male fertility found that generally the rate of pregnancy decreased with male age.
Two studies found that there is no effect of male age on pregnancy rate, while 1 study had the contradictive result that showed increase in pregnancy rate with rising male age.
In general, experts believe that age can significantly affect female and male fertilities. But it seems that the effect is more significant in women than in men.
Some experts think that the most significant decline of male fertility may occur over 50. Men in the range from 30 to 49 still have good chance to make their partner pregnant.
There are some possible reasons why aging can affect fertility in men. Here are some of these reasons.
Semen is ejaculated together with sperms. This male liquid is important to help sperms penetrate the female’s egg. For this reason, it is important to have good quality of semen.
If you are a man, there are some mechanisms that can affect your semen quality as you get older. Aging can affect the male prostate function. And we know well that men need to have good prostate to produce good quality of semen.
Your chance of getting a smooth muscle atrophy and low in ‘water & protein content’ with your prostate increases as you age. This can affect the volume and quality of semen.
In order to get your partner pregnant, there are some major keys you need to have. These keys include
- having healthy sperms,
- good quality of semen,
- normal sperm count (the amounts of sperms in the semen should be normal),
- good sperm motility,
- and normal sperm morphology (the shape and structure of sperms)
The quality of your semen can affect your sperm motility.
And as noted before, aging can increase your risk getting poor or low quality semen.
Some studies found that aging may also directly affect semen morphology, though there are also few studies showed that there is no clearly link between both conditions. This issue may be still debatable, but some experts believe that aging may be a risk factor of developing abnormal shape of sperm.
According to a study of the decline in semen quality in fertile men during the past 20 years in Paris; Auger J reported – the percent normal sperm declined by about 0.9 percent per year!
In this study, men aged 50 years-old had 18 percent decline in the percent normally shaped sperm if compared with men in the age of 30 – on average.