Unveiling the male factor: how aging and sperm defects influence IVF success

Unveiling the male factor: how aging and sperm defects influence IVF success

The Impact of Male Age on Sperm Quality and IVF Success Rates

While most discussions about fertility focus on female age, recent research confirms that male age also plays a significant role in fertility and the outcomes of assisted reproductive technologies such as in vitro fertilization (IVF). Although men are capable of producing sperm throughout their lives, advancing age can lead to changes in sperm quality and function.

First: The Impact of Age on Sperm Quality:

With advancing age, several biological changes occur in the male reproductive system, the most important of which are:

1. Decreased Sperm Count

Studies indicate that sperm count may gradually decrease with age, reducing the chances of natural fertilization.

2. Reduced Sperm Motility

Good sperm motility is essential for sperm to reach the egg. With age, both total and progressive sperm motility decline.

3. Increased Sperm DNA Fragmentation

One of the most significant age-related changes is the increased rate of DNA fragmentation in sperm, which can affect embryonic development and increase the likelihood of miscarriage.

4. Increased Genetic Mutations

Recent studies have shown that the sperm of older men may carry a greater number of genetic mutations, which could be linked to an increased risk of certain genetic disorders in children.

5. Decreased sperm quality with age

6. Increased incidence of birth defects

7. Reduced semen volume

8. Poor embryo quality

9. Reduced likelihood of implantation

10. Increased miscarriage rate

11. Increased genetic risks such as mutations, autism, and birth defects

How does sperm morphology affect IVF success?

** Reduced fertilization rate

** Reduced embryo quality

** Increased embryo stillbirth rate

** Slower embryo growth rate

** Reduced implantation rate

** Increased biochemical pregnancy rate and early pregnancy loss

Second: The Impact of Male Age on IVF Success

While the woman's age remains the most important factor in the success of assisted reproductive technologies, the man's age can affect some outcomes:

• Fertilization Rates and Embryo Quality

In most cases, the fertilization rate is not significantly affected by the man's age alone, especially when the woman is young.

• Increased Risk of Miscarriage

Advanced male age is associated with a higher rate of miscarriage after conception, often linked to increased DNA fragmentation in sperm.

• Lower live birth rates in older men:

 Some studies indicate that IVF success rates may decrease in men over 50, especially if the partner is also older.

One study showed that success rates may be lower when the man is over 51 compared to younger men.

Third: Can the effect of age be overcome?

Fortunately, modern assisted reproductive technologies can reduce the impact of some age-related factors in men, such as:

- Intracytoplasmic sperm injection (ICSI), which allows for the injection of a single sperm into the egg.

- Sperm DNA fragmentation tests to improve the selection of healthy sperm.

- Lifestyle improvements, such as quitting smoking, maintaining a healthy weight, and avoiding exposure to toxins.

- Use of antioxidants

- Treatment of varicocele, if present

- Use of advanced techniques to select the best sperm for in vitro fertilization

- Sperm retrieval from the testicle in cases of high DNA fragmentation

Although men can father children at an older age, advancing age can lead to a decline in sperm quality and an increase in sperm DNA fragmentation, which can affect the chances of pregnancy and the success rates of IVF, especially if the woman is also older. Therefore, it is advisable to carefully assess the male reproductive factors when experiencing delayed pregnancy and not focus solely on the woman's age.

Dr Najeeb Layyous  F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist