Male ageing & Fertility
Paternal age is increasing due to a number of factors and while we are aware of the negative impact that increasing female age has on fertility, more evidence is appearing suggesting increasing paternal age also has negative effects on fertility and pregnancy outome.
The effects of increased male age on Fertility
- The effects include increased infertility, decrease in IVF/ICSI outcomes and an increased rate of preterm birth.
- Increased male age is also thought to increase the chances of autism, schizophrenia, bipolar disorders and child hood leukaemia on offspring. In addition to causing infertility once the female is pregnant there are increased risks of miscarriage, premature birth and low birth weight infants, which in itself is a cause of further childhood problems.
- A major confounding factor is the fact that older men tend to reproduce with older females and so we have a double problem. It appears that the egg has an ability to deal with inferior quality sperm and this ability is reduced as the female ages. We will have to wait until sufficient studies of pregnancy outcomes between older males and young females are performed, as occurs when young donor eggs are used in couples where the male is older, to help separate out the contribution of male and female age factors.
- Less common male age associated disorders include achondroplasia, Apert Syndrome, Neurofibromatosis, Osteogenesis imperfecta, retinoblastoma, cleft lip, anencephaly, transpostion of the great vessels, ventricular and atrial septal defects (heart), neural tube defects (spine), multiple system atrophy (MSA), Tracheo-oesophageal fistula, Childhood central nervous system tumours, obsessive compulsive disorder, mood disorder and mental retardation.
Mechanisms of male age on fertility
Possible mechanisms could include reduced frequency or dysfunction with intercourse, changes to hormone production, sperm production and maturation, chromosal or DNA changes and finally epigenetic changes. However, our ability to routinely test for these other effects, other than semen analysis is at best very limited and currently of little value, as no effective treatments exist to counteract aging!
How old is old?
Different age related effects occur at different male ages and while one would like to be able to provide a simple answer this is not possible. More problems seem to occur after the age of 45.
Hence when it comes to advancing male and female age, the sooner a couple who wish to have kids begin trying, the better.
Finally the additional effects on sperm of obesity, poor lifestyle choices such as smoking, use of recreational drugs, excess alcohol and steroids only compound the age factor effects on sperm and their prolonged use could well be a cause of some of the age factors!
Sharma Reproductive Biology and Endocrinology 201513:35