We’ve all heard that smoking done by an expecting mother during pregnancy increased chances of harming a fetus that later can result in weakened fertility. That’s why the FDA recommends pregnant women abstain from the practice. But what about the effects of a father’s nicotine addiction? A recent study out of Lund University in Sweden shines some light on the questions.

We’ll be looking at:

• The study
• The analysis

Let’s get into it.

The Study

Numerous studies have been released over the years showing the link between offspring sperm count and maternal smoking habits. Men whose mothers smoked while pregnant with them show a marked reduction in sperm count than their counterparts whose mothers abstained during those 9 months. But what about men whose fathers smoked at the time of pregnancy? This question has gone unanswered until now.

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A study released in November 2018 looked at the sperm counts of over 100 men between the ages of 17 and 20 in Sweden. What they found was, controlling for maternal exposure to nicotine, men whose father smoked at the time of pregnancy had a sperm count that was half that of their counterparts. By controlling for exposure to nicotine, that means we aren’t talking about second hand smoking (which has been studied in the past). We’re talking about direct effects of paternal smoking habits on a male child’s fertility.

The Analysis

But why is this the case? Dr. Axelsson says he isn’t sure yet. More studies are needed to be able to decisively say why paternal smoking habits can result in a son’s lowered sperm count. But for now, his best guess is that we know smoking can cause damage to DNA found in sperm cells. From this, Dr. Axelsson says it could be possible that, at the time of conception, mutated or damaged gametes as a result of smoking could later result in fertility problems for a child.

It has also been shown that a father’s smoking habits can cause a daughter to have a shorter reproductive life. What we’re seeing here is signs that the health habits of a father are just as important as those of a mother. Though mothers carry the fetus, gametic health at the time of conception is all important and can cause problems if the father’s gametes are damaged or mutated in some way.