Dr Anupa Nandi
How age affects male fertility?
Updated: Dec 18, 2019
Like women, age has an impact on male fertility as well. However, unlike women who become infertile after menopause, men do not become infertile with age as sperm production (spermatogenesis) continues throughout the life and it is possible to father a biological child at any age for men.
Why is it important to know the effect of male age on fertility?
Increased age of the male partner poses greater risk to the fertility, pregnancy and the child. This is mainly due to decline in the sperm quality with age, while the sperm concentration remains largely unaltered.
1. Longer time to get pregnant: Low testosterone in older men can lead to decrease in sperm quality, decreased erectile function, and reduced libido and hence it can take longer time to get pregnancy. Sperms from older men has lower fertilising potential. A study in 2000 of 8515 pregnancies showed that men over 40 years take twice as long to conceive within 6-12 months than men less than 25 years old. Another study in 2003, of 2112 pregnancies, showed that men over 45 years four times less likely to conceive within one year compared to men less than 25 years, even if their partners were young. Lower success from IVF due to poorer embryo quality is seen in older men.
2. Increased risk of miscarriages: A large study of 23821 pregnancies showed that pregnancies fathered by men over 50 years of age has twice the risk of miscarriage compared to younger men (this is after controlling factors like maternal age and lifestyle during pregnancy). This is due to the suboptimal sperm quality of older men.
3. Increased pregnancy complications: Pregnancies in couples with older men can be complicated with pre-eclampsia, gestational diabetes, preterm birth and still birth. A study of 755,000 births in 2012 found that infants born to fathers aged over 45 years had a 48% increased risk of stillbirth and 29% greater risk for very preterm births compared to those born to younger fathers.
4. Birth defects: Sperm from older men are at increased risk of genetic abnormalities like DNA fragmentation, aneuploidy, unbalanced translocations, X linked disorders like haemophilia A, B, Duchenne Muscular dystrophy. However, these risks are low and pregnancies with older partner are currently treated as any other pregnancies without any extra genetic surveillance.
5. Risk to children: Children born to older fathers over 35 years of age are at increased risk of schizophrenia, autism and OCD (Obsessive Compulsive disorder). The mechanism of how sperm from older men causes these is not clear.
How old is too old?
There is currently no consensus as to what age should be considered as too old for men as different studies have include different age limit to define older fathers. However, the above risks increases continually over the time and is significantly increased after the age of 40 -45 years. Most sperm banks require the donors to be between ages 18-39 years.
What can men do if they're concerned about the impacts of ageing on fertility?
While it is important complete the family sooner, but life doesn’t always go as we want and it might be necessary to consider pregnancy at an older age for men.
Various factors like genetic, hormonal and anatomical changes with age, can’t be controlled.
However, various other life style factors that comes with age can certainly be taken care of to lead to a healthy pregnancy:
Stopping smoking, limiting alcohol intake, getting medical advice regarding various medical conditions or medicines which can adversely affect sperm. Men should get checked for any sexually transmitted infections.
Do mild to moderate exercise to keep their BMI in healthy range of 20-25. Men going to gym should be particularly be careful about taking any supplements as many of them can have testosterone to build muscles but can kill the sperms permanently.
Men should eat healthy balanced diet to get all the necessary minerals, vitamins and antioxidants needed for optimal sperm production and function. However, there is no medically proven diet for fertility.
Ideal temperature for sperm production is 34.5 degrees (lower than the body temperature 37 degrees). Hence men should try and avoid activities that increases the scrotal temperature like avoiding very tight underwear, take regular breaks if the job involves hot environment.
Is sperm freezing an option for men before 30 years of age?
It is certainly an option, especially for men undergoing cancer treatment (who might become infertile due to cancer treatment) or men in armed forces (at risk of injury to their genital parts) or those undergoing gender transition to female. Men undergoing IVF treatment sometimes need to freeze their sperm if their count is very low or they are unavailable due to work purpose.
This is quite safe procedure as IVF with frozen sperm is as successful as IVF with fresh sperm without any risk to children. However, not all sperm will survive the defrosting process.
In the UK, sperm can be kept frozen only for 10 years. Unless approved by a clinician (in some special circumstances) stored sperm will be discarded if not used by 10 years.
To achieve a pregnancy using the frozen sperm, the couple would need to undergo fertility treatment (like IVF) and it does not guarantee pregnancy in future. In addition, there is cost of freezing, annual storage cost and cost of the IVF in future. Needless to say that this cost varies widely between different fertility centres.
Men who are considering delaying pregnancy beyond their 40s, might also consider freezing sperm at a younger age, but they need to understand that they cannot keep it in store for more than 10 years in the UK, the cost involved and that in most circumstances they will not need to undergo fertility treatment to conceive and hence might not use the frozen sperms.
Using frozen sperm and artificial reproductive techniques in an otherwise fertile couple, makes the whole process of procreation very artificial.
We need more input in raising fertility awareness and supporting young couples to balance career and relationship so that they complete their family at a younger age before the natural decline in fertility and be more aware of the implications of delaying pregnancy.
Written by Dr Anupa Nandi