How Paternal Health Impacts Birth and Beyond

When it comes to pregnancy and birth outcomes, the spotlight has long been focused on maternal health—and rightly so. But growing research reveals a crucial piece of the puzzle that has remained largely overlooked: paternal health.

While the health and lifestyle of the person carrying the pregnancy are essential, it turns out the biological father's age, health, and habits also play a significant role in everything from fertility to fetal development, and even long-term child health.

Paternal Health: A Critical Contributor to Pregnancy Outcomes

Recent studies underscore that paternal factors—such as age, lifestyle, environmental exposures, and genetic background—directly impact a range of pregnancy and neonatal outcomes, including:

Pregnancy loss
Preterm birth (PTB)
Low birth weight
Congenital anomalies
Adverse neurodevelopmental outcomes in children

While these risks are often attributed solely to maternal health, science is making it clear: the other half of the reproductive equation matters more than we think.

Advanced Paternal Age: The Clock Is Ticking for Men, Too

Although female fertility is well known to decline with age, the risks associated with advanced paternal age (typically defined as 40 or older) are increasingly being recognised.

A 2019 study published in BMJ found that babies born to fathers over 45 had a higher risk of low birth weight and seizures, and were more likely to require intensive care after birth.
Other studies have linked older paternal age with an increased risk of autism spectrum disorder, schizophrenia, and congenital disorders in offspring.

Biologically, sperm quality declines over time. DNA mutations accumulate, and the mechanisms that repair damaged genetic material become less effective. These mutations can be passed on, potentially impacting fetal development.

Lifestyle & Environmental Exposures: A Shared Responsibility

Poor lifestyle choices—such as smoking, excessive alcohol intake, sedentary behaviour, poor diet, and drug use—can lead to oxidative stress and reduced sperm quality. These changes aren’t just about fertility—they can influence the health of the embryo and even increase the risk of pregnancy complications.

Exposure to environmental toxins, such as pesticides, heavy metals, and industrial chemicals, has also been associated with negative reproductive outcomes. Studies have shown that such exposures can cause epigenetic changes in sperm—altering how genes are expressed in the developing fetus, without changing the underlying DNA.

Genetic and Epigenetic Factors: More Than Just DNA

Men can carry certain genetic mutations or chromosomal abnormalities that may not affect their own health but can be transmitted to the offspring, increasing the risk of miscarriage or developmental disorders.

Emerging evidence also shows that the epigenetic profile of sperm—influenced by a man’s age, stress levels, and overall health—can play a role in the trajectory of pregnancy and child development. This could help explain why men's preconception health is now being considered a vital area of reproductive care.

What Can Be Done?

It’s time to reshape the narrative: pregnancy health isn’t just a maternal issue—it’s a family issue.

Here are some evidence-based recommendations for prospective fathers:

Health check-ups: Encourage men to get a preconception health assessment, especially if over 35.
Lifestyle improvements: Emphasise balanced diets, exercise, sleep, and the cessation of smoking and alcohol.
Environmental awareness: Reduce exposure to known toxins at home and work.
Stress management: Mental health is connected to physical well-being, including sperm health.
Shared responsibility: Include men in fertility conversations and prenatal planning.

The Future of Reproductive Health Must Be Inclusive

We cannot talk about improving pregnancy outcomes without acknowledging the full picture. While women have long carried the burden of reproductive responsibility, research now supports what many women have intuitively known all along: men’s health matters, too.

Integrating paternal health into public health messaging, medical research, and clinical practice could dramatically improve outcomes not just for babies, but for entire families.

Because in the end, healthy pregnancies begin with healthy people—of all genders.