Ground-breaking research has revealed that paternal age also impacts IVF success rates

Clare Goulty is delighted to welcome Professor Geeta Nargund into FR LOUNGE.

Professor Geeta Nargund
Professor Geeta Nargund

For too long, fertility and the ‘biological clock’ has been regarded solely as a woman’s issue. Ground-breaking research has revealed that paternal age also impacts IVF success rates.

Men – your age matters too!

The results are in – Professor Geeta Nargund, Founder & Medical Director at CREATE Fertility shares her insights from a study of nearly 19,000 IVF cycles. The results reveal that for women undertaking IVF aged 35-40, there’s a significant drop in the live birth rate where their male partner is 40 years+

Geeta, these are fascinating results. Please tell us more about this recent study?

Our own recent research has found that the male ‘biological clock’ plays a more significant role in the outcome of IVF treatment than was first thought. The paternal age had little impact on the chances of women under 35 or over 40 becoming pregnant, as younger womens’ eggs have a greater ability to repair the higher incidence of DNA damage typically found in older males’ sperm. Yet, as you’ve already outlined, for women aged between 35 and 40 there was a significant decline in the live birth rate if their male partner was also aged 40 and over. This is because the quality and quantity of a man’s sperm, just like a woman’s follicles (eggs), naturally decline with age.

Indeed, our research found that the live birth rate decreases from 32.8% where the paternal age is under 35 to 27.9% where the age is between 40 and 44. Additionally, where the male partner was aged over 55 years old, the live birth rate dropped even lower to 25%.

Ultimately, this points to a more complex relationship between the ageing egg and sperm at the conception stage than was previously considered. Therefore, it is important that the necessary steps are taken to garner better knowledge of the potential ability of both the egg and sperm to restore the damaging impact of the ageing process.

So, the results are telling us that men have a ‘biological clock’?

Traditionally, a woman’s fertility and ‘biological clock’ have been considered the determining factor of fertility treatment outcomes, however, as our research has determined, men do have a ‘biological clock’. In fact, in around half of cases male factor infertility is a significant contributing and important factor. As such, we can no longer ignore the effect that the male biological clock has on a couple’s fertility, as well as the short-and long-term risks an older paternal age can have on the offspring.

Advanced paternal age does not only lead to delayed conception and reduce fertilisation rates, but it can also contribute to an increased risk of miscarriages – the rate in women with male partners over the age of 45 is twice as high as those with partners under 25. Additionally, children born to men over 45 are five times more likely to have mental health problems. Indeed, they are five times more likely to have an autism spectrum disorder and 13 times more likely to receive an ADHD diagnosis.

The concept of a male ‘biological clock’ seems to go against the media-fuelled narrative of older men fathering children into their 60’s and beyond. How can we dispel stereotypes of older fathers in the press and ensure men are aware of the factors impacting their fertility?

Recently stories of older male celebrities have been hitting the headlines, such as Robert De Niro and Al Pacino having children well into their ‘golden years’. This news of male celebrities fathering children much later in life only cements the false and particularly dangerous belief that men have no biological clock. For this reason, it is vital that men at all ages are educated about the fact that age is not just a number and it does impact their fertility; Robert and AI are the minority, and not the norm.

For a long time, I have campaigned for the national curriculum to include a focus on fertility education. Now, as our research has confirmed, it is vital that both young females and males have the knowledge to make empowered and educated decisions about their futures, as well as how they can best look after their fertility health.

Geeta, in your view, when’s the optimum age for men’s fertility?

We now know that fertility is not solely a women’s issue, but getting pregnant does also come down to a multitude of factors.

Our studies show that after the male age of 40, the chance of a woman aged over 35 getting pregnant is reduced.

A woman’s fertility begins to decline from the age of 35 and as such it is important for couples trying to conceive naturally that they take a holistic view of their situation. That is, both male and female part fertility health and lifestyle choices, which can also affect a couple’s chances of getting pregnant. Couples struggling to conceive may wish to consider taking fertility tests to determine whether there might be an issue with male or female fertility health.

How can men check their fertility? What sort of tests are available?

Generally, if both partners are under the age of 35 and have been trying to get pregnant for 12 months or more without success, or if the female is over the age of 35 and the male is over 40 and they have been unable to conceive after six months, then speaking to a doctor is crucial as they can carry out several tests that will determine the fertility of the couple.

For men, this might involve a detailed semen analysis to check the sperm density, motility, and morphology. Other areas that the analysis might cover include appearance, pH, volume and, agglutination (stickiness). It is also important to note that prior to this test, the male partner abstains from ejaculation no less than two days and no more than five days before, so not to alter results, and if the male partner has recently had an infection or is on antibiotics, he should make sure to reschedule his appointment as this also might lead to suboptimal results.

Following the appointment, if there are issues with sperm quantity or quality then they can have a consultation with a fertility consultant to get advice on how to improve their sperm. Where it is appropriate, and if there is a moderate to severe male factor problem, then intracytoplasmic sperm injection (ICSI), where the sperm is injected directly into the egg, is usually the recommended procedure.

What are the most common causes of male infertility?

Lifestyle factors can play a large part in negatively affecting fertility. For instance, a sedentary lifestyle and smoking can contribute to reduced fertility. It is also important that men and women consider other factors such as certain genetic or medical conditions, including an underactive thyroid or sexually transmitted infections that can cause infertility.

In addition, specific disorders of male (reproductive) organs can also be a reason for infertility. These might include blockage of the ejaculatory ducts, undescended testis, testicular tumours, or varicoceles (prominent veins). There are also severe cases of azoospermia, where the seminal fluid has no sperm at all, which is known to affect 1% of the male population.

Can men improve their fertility?

While it is essential that couples wanting to get pregnant are having unprotected sex at the correct time of the female partner’s menstrual cycle, certain lifestyle changes can improve fertility and help achieve conception.

For example, eating a healthy and balanced diet, as well as lowering stress levels, no smoking, reducing alcohol consumption and regular exercise are all factors that will help maintain a man’s normal BMI, a key element in maximising fertility.

However, it is crucial to remember that while these lifestyle changes can go a long way in bettering a man’s fertility health, if a couple are finding it hard to conceive and have been trying for an extended period of time, then they should look to consult a medical professional, as assisted reproductive technologies can help.

Do you think there’s a global decline in male fertility? Why is that?

In April (2023), the World Health Organisation revealed that 1 in 6 people worldwide are affected by infertility – this is around 17.5% of the adult population. Additionally, on Thursday 8th June, research from the University of Oxford’s Leverhulme Centre for Demographic Science revealed that live birth rates in England and Wales fell to their lowest recorded level over the past decade.

These two equally shocking statistics not only starkly point to a global decline in male fertility, but also confirm that we are currently experiencing a global fertility crisis, something that poses a pressing and increasing threat to our global society. This is because the global fertility rate currently stands at 2.3 and once the fertility rate drops below 2.1, we will surpass our ‘replacement rate’ meaning that the global population is considered unstable as one generation is unable to replace the next.

Education is key and both men and women must be aware of the rate at which fertility declines, as well as the lifestyle choices that can affect fertility health. It is through fully understanding our bodies and the medical tests and treatment options available that will allow men, women and couples to take responsibility over their fertility health.

What does the future look like for male fertility?

With the right education at an early age, the future looks positive for male fertility. Indeed, educating young people on the factors that impact their fertility as well as the effect that age has on their ability to start a family, will provide them with the important knowledge that can tackle many instances of infertility globally. Indeed, to halt the infertility crisis we are currently experiencing, it is vital that young people are armed with the right information to take the necessary steps to protect their fertility or secure an early diagnosis and treatment if needed.

One way we can achieve this would be by ensuring that the national curriculum’s focus pivots from just avoiding pregnancy to also including the topic of infertility prevention. This way the future of male fertility starts in the classroom. Knowledge is power.

Many thanks to Professor Geeta Nargund for joining Clare Goulty in FR LOUNGE.

Geeta can be reached at:

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Clare Goulty
Editor-in-Chief and published Author. Skilled in Brand Strategy, Campaign Management, Magazine Publishing, Content Strategy & Content Management, Magazine Design & Marketing. Strong media and communication professional graduated from Canterbury Business School with MBS & MBA.
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