Child health problems 'linked to father's age'

A wide range of disorders and problems in school-age children have been linked to delayed fatherhood. Increased rates of autism, attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, suicide attempts and substance abuse problems were all reported.

The study

The study, in JAMA Psychiatry, suggests mutated sperm were to blame. However, experts say the benefits older dads bring may outweigh any problems. The investigation by Indiana University, in the US, and Sweden's Karolinska Institute has been described as the largest and one of the best designed studies on the issue. The researchers looked at 2.6 million people and at the difference between siblings born to the same father as it accounts for differences in upbringing between families.

Comparing

Comparing children of a 45-year-old dad to those of a 24-year-old father it indicated:

• autism was more than three times as likely
• a 13-fold increased risk of ADHD
• double the risk of a psychotic disorder
• 25 times more likely to have bipolar disorder
• 2.5 times more likely to have suicidal behaviour or problems with drugs
• lower scores at school

There was no starting point after which the risk started to increase. Rather any increase in age had an associated increase in risk.

However, the overall risk is likely to remain low. The problem is small increases in risk scaled up over millions of people having children later. It can lead to an increased incidence of such disorders.

Researchers speak

Dr Brian D'Onofrio (one of the researchers) was shocked by the findings. Findings suggested a higher risk than previously estimated. He told the BBC: "The implications of the study is that delaying childbearing is also associated with increased risk for psychiatric and academic problems in the offspring. "The study adds to a growing body of research, that suggests families, doctors, and society as a whole must consider both the pros and cons of delaying childbearing."

Faulty sperm

As the sperm-making mechanism ages, so too do the number of errors. Older sperm have more mutations which may be damaging. Dr James MacCabe, senior lecturer in psychosis at the Institute of Psychiatry: "I would make the point very strongly that men should not decide on whether or when to have children on a single study, or cumulative studies." He said the risks were low. And that even a doubling or trebling of risk would still affect a small proportion of people. "With the demographic change we have seen in the last decade, on a population level this is a concern. We might expect higher rates of psychoses now and in the future." He added that older dads bring many advantages such as more stable relationships and higher income. This "probably outweigh" any risks.

Frequently Asked Questions

Does a father's age affect a child's health in the UK?

Research suggests that advanced paternal age may be linked to increased risks of certain conditions in children, including autism, ADHD, and bipolar disorder. A major study found that children of fathers aged 45 had significantly higher risks compared to those with younger fathers. However, the overall risk remains relatively low, and many older fathers have perfectly healthy children.

What age is considered an older father for fertility purposes?

Whilst there's no official NHS definition of "advanced paternal age," research typically considers fathers over 40-45 as being in the older category. Unlike women, men don't have a definitive cut-off for fertility, but sperm quality can decline gradually with age, potentially affecting both conception and child health outcomes.

Should I be worried about having a baby if my partner is over 40?

Whilst the study shows increased relative risks, it's important to recognise that the absolute risk of conditions like autism or ADHD remains low for most families. The NHS recommends that couples trying to conceive focus on overall health, including maintaining a healthy weight, reducing alcohol intake, and not smoking, regardless of age.

Does the NHS offer fertility testing for older men trying to conceive?

The NHS can provide semen analysis as part of fertility investigations if a couple has been trying to conceive for over a year without success. NICE guidelines recommend that both partners should be assessed, though funding and waiting times vary by local Integrated Care Board (formerly CCG). Remember, around 1 in 7 UK couples experience fertility issues, so seeking help is perfectly normal.

Can lifestyle changes improve sperm quality in older men?

Yes, the NHS recommends several lifestyle modifications that may help improve sperm health at any age. These include maintaining a healthy BMI, stopping smoking, limiting alcohol consumption, and avoiding tight underwear. Taking supplements containing zinc and folic acid may also support sperm health, though it's best to discuss this with your GP.

Are there genetic tests available for older fathers on the NHS?

The NHS doesn't routinely offer genetic screening based solely on paternal age. However, all pregnant women in the UK are offered screening for certain chromosomal conditions regardless of parental age. If there's a family history of genetic disorders, your GP can refer you to NHS genetic counselling services to discuss your options before trying to conceive.

What support is available if my child is diagnosed with autism or ADHD?

The NHS provides comprehensive support for children diagnosed with developmental conditions, including assessment through Child and Adolescent Mental Health Services (CAMHS) and educational support through local authorities. Early intervention is key, so if you have concerns about your child's development, speak to your GP or health visitor who can arrange appropriate referrals.