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Health Information | 07/19/2023

Why it is Becoming Harder for Men to Become Fathers

By  Dr. Danielle Vitiello
Father with baby

Infertility is a growing challenge, with nearly 1 in 6 people worldwide affected by it, according to a recent report by the World Health Organization. About 40% of infertility cases can be traced to male factors, with the major drivers being sperm count and semen quality as found in a study by Harvard Medical School, but male infertility may also be caused by a range of other medical conditions. The exact cause of male infertility can often be difficult to diagnose, so it is important to seek medical advice if you are having difficulty conceiving. With the right diagnosis and treatment, many couples can still achieve a successful pregnancy.

The Importance of Sperm Health

Good sperm quality is crucial for fertility because it directly impacts a couple's ability to conceive a child. Sperm quality refers to various characteristics of sperm cells that determine their ability to fertilize an egg successfully. Here are a few reasons why good sperm quality is important for fertility:

1. Sperm Count: The number of sperm cells present in semen significantly affects fertility. A higher sperm count increases the chances of one sperm reaching and fertilizing the egg. If the sperm count is low, it reduces the likelihood of successful fertilization.

2. Sperm Motility: Motility refers to the sperm's ability to swim forward and reach the egg. Good sperm motility is vital because sperm must navigate through the female reproductive system to meet the egg. If sperm motility is poor, the sperm may struggle to reach the egg, reducing the chances of fertilization.

3. Sperm Morphology: The shape and structure of sperm are crucial for fertility. Sperm with abnormal morphology may have difficulty penetrating the outer layer of the egg or binding to it. Normal sperm morphology is essential for successful fertilization.

It's important to note that fertility issues can arise from various factors, including female reproductive health, ovulation, and other factors unrelated to sperm quality. However, optimizing sperm quality through healthy lifestyle choices, such as maintaining a balanced diet, regular exercise, avoiding excessive alcohol and drug use, and managing stress, can improve the chances of successful conception.

Is Male Infertility Common?

Male fertility issues appear to be on the rise. Previously the EARTH study found that among men seeking infertility treatment, sperm count, and quality had declined as much as 42% between the years of 2000-2017 and continue to drop annually.

Reasons for Male Infertility

There are a variety of different factors contributing to male infertility, including genetic abnormalities, hormonal imbalances, environmental and lifestyle factors, and certain medical conditions such as diabetes. While the exact causes of infertility may vary from person to person, understanding these underlying factors is crucial in developing effective treatments and interventions to address this complex and challenging issue. Let’s explore some of the most common causes of male infertility, ranging from physical and medical conditions to lifestyle and environmental factors.

Male Biological Clock

While women are often warned about their biological clock and the risks of delaying pregnancy, men also face age-related fertility decline. Studies show that male fertility starts declining after age 40, with lower sperm counts and quality, as well as higher risks of miscarriage and genetic disorders in children. The children of older fathers also have higher risks for conditions like autism and schizophrenia. Given these risks, men who want to have children later in life should consider freezing their sperm when younger to expand their reproductive options. Overall, both women and men should be aware of how age affects fertility and health risks for children when planning parenthood.

Genetic Reasons

Men can experience infertility for a variety of genetic reasons. These genetic conditions can impact the development and function of the male reproductive system, resulting in low sperm counts or decreased sperm mobility. Genetic testing is often recommended for men with unexplained infertility to determine if an underlying genetic cause may be a factor. While some genetic causes cannot be treated, others may respond to medical intervention or assisted reproductive techniques.


A balanced diet rich in nutrients is essential for male fertility and reproductive health. Studies show that diets high in saturated fat and sugar can negatively impact sperm quality, while foods like fish, nuts, and leafy greens may help boost fertility. For example, omega-3 fatty acids found in fish and walnuts have been shown to improve sperm count, motility, and morphology. By focusing on a balanced diet of lean proteins, healthy fats, and plenty of fruits and vegetables, men can support healthy fertility and reproductive function.


Smoking has detrimental effects on male fertility and reproductive health. Studies show that men who smoke have significantly lower sperm counts as well as lower sperm quality and motility. Secondhand smoke exposure poses risks as well. According to the World Health Organization, smoking decreases pregnancy rates by 44% and lowers success rates of IVF treatments. The toxins in cigarette smoke damage DNA in sperm, and the heat from smoking decreases testicular function. 

Marijuana use has also been linked to male infertility, with studies showing that regular marijuana use is associated with decreased sperm count and concentration, as well as abnormal sperm morphology. 

Environment: Plastics, Chemicals, and Environmental Pollutants

Environmental pollutants such as BPA, pesticides, and chemicals are pervasive in today's world and pose serious risks to human health, including male fertility. Studies show that exposure to BPA, a chemical found in plastics and receipts, is linked to decreased sperm count and quality. Pesticides sprayed on crops and lawns contain chemicals that may disrupt hormones and impair fertility. Other pollutants like dioxins, PCBs, and heavy metals have also been shown to damage sperm cells, reduce testosterone, and increase the risk of testicular cancer. By reducing exposure to these harmful chemicals and toxins, men can help safeguard their reproductive health and fertility.


Sleep has a significant impact on male infertility, with several studies pointing towards a direct correlation between sleep patterns and sperm count. The research shows that both too much and too little sleep can be detrimental to male fertility. In particular, sleeping for more than nine hours is linked to a 40% reduction in sperm count, while getting less than 6.5 hours of sleep results in a 25% reduction. So, what is the optimal sleep for male fertility? According to experts, it's 7-7.5 hours a day, and the timing of your sleep also plays a role. Therefore, it's important for men trying to conceive to not only pay attention to their diet and lifestyle but also prioritize getting quality sleep.

How We Can Help

If you are experiencing difficulty conceiving, our reproductive health specialists are here to help guide you, as well as discuss fertility treatment options that can help you grow your family. 


Schedule a Consultation with an Atrius Health Fertility Specialist

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Dr Danielle Vitiello

About The Author

Dr. Danielle Vitiello

Dr. Danielle Vitiello graduated with honors in chemistry from Boston University. She received her medical degree from the University of Vermont where she also received a Ph.D. in molecular genetics. She completed her internship and residency in obstetrics and gynecology at Yale-New Haven Hospital and continued at Yale to complete her fellowship in reproductive endocrinology and infertility.

Before returning to the Boston area, Dr. Vitiello worked at Yale-New Haven Hospital where she was on the faculty of Yale University’s Department of Obstetrics and Gynecology. She is certified in obstetrics and gynecology by the American Board of Obstetrics and Gynecology and is a fellow of the American College of Obstetrics and Gynecology.

A distinguished award recipient for her clinically applied research and for excellence in teaching, Dr. Vitiello is a member of the Alpha Omega Alpha Honor Medical Society and numerous other academic and medical societies, including the American Society for Reproductive Medicine.

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