We try and give our children the best start in life, but sometimes we do things that harm them without even knowing it. In a recent study, researchers from the University of Pennsylvania School of Medicine found that men who use cocaine at the time of conception may put their sons at risk for learning disabilities and memory loss. The finding further adds to the list of unexpected traits we can pass on to our sons.

The study, published online in Molecular Psychiatry, found that sons, but not daughters, of male rats that consumed cocaine for an extended period of time experienced significant memory loss. These mice also had impaired synaptic plasticity in their hippocampus, a brain region critical for learning and spatial navigation in humans and rodents, PsyPost reported.

Read: This Is Your Brain On Cocaine: Dopamine Buildup Excites Brain's Reward Center, But At What Price?

“These results suggest that the sons of male cocaine addicts may be at risk for learning deficits,” said senior author R. Christopher Pierce, in a recent statement on ScienceDaily.

Upon closer inspection, the team saw that cocaine abuse in fathers altered the chemical marks in the brains of their sons, regardless of the fact that these offspring were never exposed to cocaine. This changed the expression of certain genes involved with memory formation in the brains of the young male mice. Specifically, the sons of cocaine-using mice had low levels of a molecule known as D-serine. This molecule is essential for memory formation and learning. The team is now looking into using these findings to potentially reverse the effects of paternal cocaine abuse in male offspring.


Cocaine is not the only drug that can lead to unexpected traits in offspring. A 2013 study found that marijuana use had interesting effects on the male offspring of mice for up to three generations. Sons of mice exposed to marijuana had lowered motivation and experienced more weight gain, compared to male offspring of mice given a placebo injection.

While the research showed a clear association between lower motivation and weight gain in sons, grandsons, and even great grandsons of mice exposed to marijuana, the researchers admitted that they were “nowhere close to figuring out how it is that these mechanisms are passed on across generations,” Medpage Today reported.

In Vitro Fertilization

According to a 2016 study, male babies conceived via IVF may experience reduced fertility in adulthood. Men born from ICSI had almost half the sperm concentration of naturally conceived men, as well as a 62 percent lower sperm count, and 66 percent lower sperm motility, or how well sperm can move. They were about three times more likely to have sperm concentrations below the "normal" level.

Despite this risk, many parents reported that they were still not deterred from having a child via IVF, for if their son did inevitably develop these fertility issues he could also use IVF to start a family of his own one day.

Source: Wimmer ME, Briand LA, Fant B, et al. Paternal cocaine taking elicits epigenetic remodeling and memory deficits in male progeny. Molecular Psychiatry. 2017

See Also:

Going Bald Isn't Your Mother's Fault; Maternal Genetics Are Not To Blame

Cannabis Effects Passed Down Three Generations In Rats