Want to Be a New Father?
Quit Using Cannabis First

Advocates for the expanded use of marijuana are quick to promote the few medical benefits of this drug. However, they seem to be deaf to the many problems caused by cannabis consumption. Included in these problems is this: cannabis can make it harder to father a child or could create serious, even life-threatening problems for the child.

Any man wishing to create a family should know about the harms of using cannabis. He should also be educated on the increased risks of sudden infant death, miscarriage, or even future psychosis. In fact, every couple planning a family should understand the relationship between marijuana and fertility and all the possible damage that can result from a father’s use of the drug.

New Data on Cannabis’ Effects on Prospective Fathers

For many years, popular opinion has held that the mother’s health and behavior before and during pregnancy were the only factors that affected a baby’s health. That’s all changing. New research suggests that paternal cannabis use in the months before conception can have a profound effect on the new baby. In 2025, recent research has made the connection between pre-conception cannabis use by fathers and injury to babies obvious.

Cannabis’s Affect on Fertility

Canadian researchers found that cannabis has adverse effects on fertility in both men and women. Their study published in 2020 stated, “Marijuana can have a negative effect on fertility for both men and women and can create problems when a woman uses marijuana while pregnant.”

“Marijuana can have a negative effect on fertility for both men and women and can create problems when a woman uses marijuana while pregnant.”

Further, the authors of a Norwegian study stated that cannabis impacts “sperm motility, viability, and function.” The reduction of these qualities in human sperm reduces a father’s ability to produce a child.

Cannabis Use and Risk of Miscarriage

In yet another concerning discovery, researchers at Boston University School of Public Health determined that paternal marijuana use is also connected to partner miscarriage. Their 2019 study found that when men use marijuana one or more times per week, their partner is more than twice as likely to miscarry than partners of men who do not use marijuana.

Paternal Cannabis Use and the Risk of Sudden Infant Death Syndrome (SIDS)

The study from Norway also revealed a direct connection between paternal marijuana use and sudden infant death syndrome. The authors stated, “Paternal marijuana use during the period of conception, pregnancy, and postnatally has been found to be significantly associated with sudden infant death syndrome.”

Preterm Birth and Low Birth Weight

A study carried out over 20 years found a clear association between cannabis use and premature birth as well as low birth weight. Babies whose parents had used cannabis daily between the ages of 15 and 17 had a greater risk of being born either prematurely or with low birth weight.

• Babies born to cannabis-using parents were born, on average, one week earlier than babies born to parents who did not use cannabis at these early ages.
• Babies born to these parents had a six-fold risk of pre-term birth.
• Similarly, there was nearly a six-fold risk of low birth weight.

Both prematurity and low birth weight are risk factors for serious health problems, specifically the following:

• Neonatal death
• Greater risks for nervous system disorders and disabilities
• Increased risk of cardiovascular and metabolic diseases

Cannabis use by both mothers and fathers was considered during this study. Every parent should be aware of the profound effect cannabis use can have on future childbearing.

Brain Impairment Due to Cannabis Use

The damage caused by pre-conception cannabis use does not stop with the harm already listed, as serious as those harms are. There is even more research that points to damage to the fetal brain. A 2020 animal study at Duke University found that changes in the father’s sperm affected how the fetal brains developed in the womb.

Potential Psychosis for the Child

Cannabis use by fathers before conception is associated with psychotic-like experiences in the offspring by the time the child reaches ten years of age. This age was chosen as a cut-off point because it is typically prior to the age that the child might begin using cannabis products. According to this 2018 study, when a father-to-be uses cannabis regularly in the months leading up to conception, his offspring’s risk for psychotic experiences and other mental issues almost doubles.

Association Between Cannabis and DNA Changes

How is it possible that a father’s cannabis use before conception can affect the child’s health and well-being? The study showing the association between cannabis use and SIDS states, “paternal lifestyle during sperm development may also have an impact by inducing modifications or damage to the genetic material.”

According to the Boston University study author Alyssa Harlow, “Given that the human embryo is comprised 50 percent of the male’s genes, there’s been emerging interest in studying the role that men play. There are [cannabinoid] receptors in human testicular tissue and sperm, and when a man uses marijuana, THC binds to these receptors.”

Another study in 2024 points out that “high potency cannabis leaves a unique signature on DNA related to mechanisms around the immune system and energy production.” The fact that cannabis impacts the father’s DNA is vital information for parents-to-be. They should know that drug use could ruin their plans to create healthy, happy children.

A Bright Spot in Cannabis Research

The Duke University animal study also found that ceasing cannabis use for 11 weeks reduced the number of alterations in the sperm. Eleven weeks is how long new sperm need to fully mature. At that point, healthier sperm can make healthier babies.

Men who wish to father children will have a greater chance of being fertile and producing healthy sperm if they follow these guidelines from the Centers for Disease Control and Prevention:

• Maintain a healthy weight
• Refrain from using any tobacco products
• Avoiding cannabis or other drug use
• Get moderate exercise (but not extreme exercise or sports)

When in Need, Seek Help from an Addiction Treatment Center

It’s one thing to educate a prospective father on how to improve the health of his future baby. It may be a different thing entirely for this person to stop using cannabis. The Substance Abuse and Mental Health Services Administration reports that more than 19 million Americans have a marijuana use disorder. That means that these people continue to use cannabis despite the harm it causes them.

The effects of substance abuse extend far beyond the individual. Substance abuse affects the person’s spouse, children, employer, friends, family, and community. A person who has lost control of their drug abuse may not see the harm. For that reason, drug rehabilitation is often needed to help a person get sober and healthy once again. Once men complete rehab and there is no more marijuana use, they have a chance to once again produce healthy sperm. Their risk of having a baby born early or with low birth weight or of losing a baby to SIDS or miscarriage will be lower. Avoiding these problems or tragedies makes for greater happiness for the individual and the whole family.

If you know someone who cannot stop using marijuana or other substances on his own, please contact Narconon today. Nearly sixty years in drug rehabilitation have shown that this program gets results. The testament to the program’s success is in the tens of thousands of individuals who have been able to reclaim their sober, healthy lives thanks to the program. To take the first step toward a better future for your loved one, call Narconon today.

Sources:

• “The use of cannabis and its perceptions of its effect on fertility among infertile patients.” National Library of Medicine, 2020. NLM

• “Pre conception use of cannabis and cocaine among men with pregnant partners.” Sage Journals, 2019. Sage Journals

• ”Male Marijuana Use Might Double the Risk of Partner’s Miscarriage.” The Brink, Boston University, 2019. Boston University

• “Cannabis and tobacco use prior to pregnancy and subsequent offspring birth outcomes.” Nature.com, 2021. Nature.com

• “Study Shows Impact of Paternal Marijuana Exposure on the Brains of Offspring.” Duke Health, 2020. Duke Health

• “Maternal and paternal cannabis use during pregnancy and the risk of psychotic-like experiences in the offspring.” ScienceDirect, 2018. ScienceDirect

• “High potency cannabis use leaves unique signature on DNA, study shows.” ScienceDaily, 2024. ScienceDaily

• “Infertility: Frequently Asked Questions.” Centers For Disease Control and Prevention, 2024. CDC

• “Effects of physical exercises on semen quality and reproductive outcomes in male infertility.” National Library of Medicine, 2019. NLM

• “National Survey on Drug Use and Health, 2023.” Substance Abuse and Mental Health Services Administration, 2024. SAMHSA. (Table 5.1A)

• “Narconon Global Mission.” Narconon.org, undated. Narconon.org

• “Drug Rehab.” Narconon.org, undated. Narconon.org

Clinically reviewed by Matt Hawk BS, CADC-II, ICADC