While women who are pregnant, or are planning to become pregnant, have known for a long time that they have to be very careful with their alcohol consumption, a new study with contributions from Quebec researchers warns that the same probably applies to men.

"Ten or 15 years ago, when people were proposing that a man's living conditions might have an impact on fetal development, we just didn't believe it," said one of the study's authors, professor Claude Robert of Laval University's department of animal sciences.

"We thought there was no chance that a male's lifestyle would have an impact on fetal development."

All the pressure was therefore put on the mother, he adds, since "she is the one who prepares the ovum, she is the one who prepares the uterus... but now we realize that the male also has an impact."

A study published in Scientific Reports by Robert, who is also a researcher at Laval University's Centre for Research in Reproduction, Development and Intergenerational Health (CRDSI), and by scientists at Texas A&M University, suggests that fathers also have a role to play in preventing fetal alcohol spectrum disorder.

They found that in male mice that had consumed the human equivalent of five drinks in two hours each day for 70 days, proteins associated with sperm genetic material appeared in a modified biochemical form that affected the transcription of genes important for fetal development.

When these male mice were crossed with females that had never been exposed to alcohol, fetal development was affected.

The affected regions included those involved in the development of neurons and the craniofacial conformation of mice. In humans, prenatal alcohol exposure adversely affects cognitive development and certain facial features, which may suggest that the mechanism observed in mice is also at play in humans.

"Maybe in a few years, we'll be telling parents who want to have children that the father should have a healthy, balanced lifestyle to avoid long-term [adverse] impacts [on the baby]," Robert said.

Especially since this study only looked at one facet of lifestyle, namely alcohol consumption, we cannot rule out that other components — such as physical activity, smoking, or the quality of sleep and diet — also have an impact on sperm quality.

Finally, one should keep in mind that spermatogenesis can take 60 or 70 days — in other words, the sperm that fertilizes the egg that night began forming two months earlier.

A man who wants to start a family, therefore, shouldn't be making last-minute plans to adopt the best possible living habits.

"It's not the week before that you have to think about it," professor Robert summarized.

This report by The Canadian Press was first published in French on June 27, 2022.