We hear a lot about women’s biological clock and how age affects the chance of pregnancy.

New research shows men’s fertility is also affected by age. When dads are over 50, the risk of pregnancy complications increases.

Data from more than 46 million births in the United States between 2011 and 2022 compared fathers in their 30s with fathers in their 50s.

While taking into account the age of the mother and other factors known to affect pregnancy outcomes, the researchers found every ten-year increase in paternal age was linked to more complications.

The researchers found that compared to couples where the father was aged 30–39, for couples where the dad was in his 50s, there was a:

• 16% increased risk of preterm birth
• 14% increased risk of low birth weight
• 13% increase in gestational diabetes.

The older fathers were also twice as likely to have used assisted reproductive technology, including IVF, to conceive than their younger counterparts.

Dads are getting older

In this US study, the mean age of all fathers increased from 30.8 years in 2011 to 32.1 years in 2022.

In that same period, the proportion of men aged 50 years or older fathering a child increased from 1.1% to 1.3%.

We don’t know the proportion of men over 50 years who father children in Australia, but data shows the average age of fathers has increased.

In 1975 the median age of Australian dads was 28.6 years. This jumped to 33.7 years in 2022.

How male age affects getting pregnant

As we know from media reports of celebrity dads, men produce sperm from puberty throughout life and can father children well into old age.

However, there is a noticeable decline in sperm quality from about age 40.

Female partners of older men take longer to achieve pregnancy than those with younger partners.

A study of the effect of male age on time to pregnancy showed women with male partners aged 45 or older were almost five times more likely to take more than a year to conceive compared to those with partners aged 25 or under. More than three quarters (76.8%) of men under the age of 25 years impregnated their female partners within six months, compared with just over half (52.9%) of men over the age of 45.

Pooled data from ten studies showed that partners of older men are also more likely to experience miscarriage. Compared to couples where the male was aged 25 to 29 years, paternal age over 45 years increased the risk of miscarriage by 43%.

Older men are more likely to need IVF

Outcomes of assisted reproductive technology, such as IVF, are also influenced by the age of the male partner.

A review of studies in couples using assisted reproductive technologies found paternal age under 40 years reduced the risk of miscarriage by about 25% compared to couples with men aged over 40.

Having a male under 40 years also almost doubled the chance of a live birth per treatment cycle. With a man over 40, 17.6% of treatment rounds resulted in a live birth, compared to 28.4% when the male was under 40.

How does male age affect the health outcomes of children?

As a result of age-related changes in sperm DNA, the children of older fathers have increased risk of a number of conditions. Autism, schizophrenia, bipolar disorders and leukaemia have been linked to the father’s advanced years.

A review of studies assessing the impact of advanced paternal age reported that children of older fathers have increased rates of psychiatric disease and behavioural impairments.

But while the increased risk of adverse health outcomes linked to older paternal age is real, the magnitude of the effect is modest. It’s important to remember that an increase in a very small risk is still a small risk and most children of older fathers are born healthy and develop well.

Improving your health can improve your fertility

In addition to the effects of older age, some chronic conditions that affect fertility and reproductive outcomes become more common as men get older. They include obesity and diabetes which affect sperm quality by lowering testosterone levels.

While we can’t change our age, some lifestyle factors that increase the risk of pregnancy complications and reduce fertility, can be tackled. They include:

• smoking
• recreational drug taking
• anabolic steroid use
• heavy alcohol consumption.

Get the facts about the male biological clock

Research shows men want children as much as women do. And most men want at least two children.

Yet most men lack knowledge about the limitations of female and male fertility and overestimate the chance of getting pregnant, with and without assisted reproductive technologies.

We need better public education, starting at school, to improve awareness of the impact of male and female age on reproductive outcomes and help people have healthy babies.

For men wanting to improve their chance of conceiving, the government-funded sites Healthy Male and Your Fertility are a good place to start. These offer evidence-based and accessible information about reproductive health, and tips to improve your reproductive health and give your children the best start in life.

Karin Hammarberg, Senior Research Fellow, Global and Women’s Health, School of Public Health & Preventive Medicine, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Around one in 20 people has attention-deficit hyperactivity disorder (ADHD). It’s one of the most common neurodevelopmental disorders in childhood and often continues into adulthood.

ADHD is diagnosed when people experience problems with inattention and/or hyperactivity and impulsivity that negatively impacts them at school or work, in social settings and at home.

Some people call the condition attention-deficit disorder, or ADD. So what’s the difference?

In short, what was previously called ADD is now known as ADHD. So how did we get here?

Let’s start with some history

The first clinical description of children with inattention, hyperactivity and impulsivity was in 1902. British paediatrician Professor George Still presented a series of lectures about his observations of 43 children who were defiant, aggressive, undisciplined and extremely emotional or passionate.

Since then, our understanding of the condition evolved and made its way into the Diagnostic and Statistical Manual of Mental Disorders, known as the DSM. Clinicians use the DSM to diagnose mental health and neurodevelopmental conditions.

The first DSM, published in 1952, did not include a specific related child or adolescent category. But the second edition, published in 1968, included a section on behaviour disorders in young people. It referred to ADHD-type characteristics as “hyperkinetic reaction of childhood or adolescence”. This described the excessive, involuntary movement of children with the disorder.

In the early 1980s, the third DSM added a condition it called “attention deficit disorder”, listing two types: attention deficit disorder with hyperactivity (ADDH) and attention deficit disorder as the subtype without the hyperactivity.

However, seven years later, a revised DSM (DSM-III-R) replaced ADD (and its two sub-types) with ADHD and three sub-types we have today:

• predominantly inattentive
• predominantly hyperactive-impulsive
• combined.

Why change ADD to ADHD?

ADHD replaced ADD in the DSM-III-R in 1987 for a number of reasons.

First was the controversy and debate over the presence or absence of hyperactivity: the “H” in ADHD. When ADD was initially named, little research had been done to determine the similarities and differences between the two sub-types.

The next issue was around the term “attention-deficit” and whether these deficits were similar or different across both sub-types. Questions also arose about the extent of these differences: if these sub-types were so different, were they actually different conditions?

Meanwhile, a new focus on inattention (an “attention deficit”) recognised that children with inattentive behaviours may not necessarily be disruptive and challenging but are more likely to be forgetful and daydreamers.

Why do some people use the term ADD?

There was a surge of diagnoses in the 1980s. So it’s understandable that some people still hold onto the term ADD.

Some may identify as having ADD because out of habit, because this is what they were originally diagnosed with or because they don’t have hyperactivity/impulsivity traits.

Others who don’t have ADHD may use the term they came across in the 80s or 90s, not knowing the terminology has changed.

How is ADHD currently diagnosed?

The three sub-types of ADHD, outlined in the DSM-5 are:

• predominantly inattentive. People with the inattentive sub-type have difficulty sustaining concentration, are easily distracted and forgetful, lose things frequently, and are unable to follow detailed instructions
• predominantly hyperactive-impulsive. Those with this sub-type find it hard to be still, need to move constantly in structured situations, frequently interrupt others, talk non-stop and struggle with self control
• combined. Those with the combined sub-type experience the characteristics of those who are inattentive and hyperactive-impulsive.

ADHD diagnoses continue to rise among children and adults. And while ADHD was commonly diagnosed in boys, more recently we have seen growing numbers of girls and women seeking diagnoses.

However, some international experts contest the expanded definition of ADHD, driven by clinical practice in the United States. They argue the challenges of unwanted behaviours and educational outcomes for young people with the condition are uniquely shaped by each country’s cultural, political and local factors.

Regardless of the name change to reflect what we know about the condition, ADHD continues to impact educational, social and life situations of many children, adolescents and adults.

Kathy Gibbs, Program Director for the Bachelor of Education, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.