All the peace-and-harmony mythology that surrounds smoking marijuana is better in the movies than in real life. It was pretty funny watching Jack Nicholson as George in "Easy Rider" trying pot for the first time and stammering, "You — you mean marijuana?"

But new research shows it's not really a laughing matter.

A lab study in the journal Toxicological Studies found that intense but short-term exposure to pot smoke (you don't even have to inhale from the joint, just be in the room) lowers sperm count and slows sperm motility in male mice and in their future offspring.

This reinforces previous human studies that showed stoned sperm reduces fertility.

There's also evidence that more and more women are smoking pot while pregnant. According to the National Institute on Drug Abuse, there has been a significant increase in the number of pregnant women seeking treatment for marijuana abuse over the past 10 years.

And one study found that about 20% of pregnant women ages 24 and younger screened positive for marijuana. 

Animal studies suggest that using marijuana while pregnant increases the risk of miscarriage. Some associations have been found between marijuana use during pregnancy and developmental and hyperactivity disorders in kids. Research has also shown that pregnant women who use marijuana have a 2.3 times greater risk of stillbirth. 

So ask yourself: Do you want healthy children? If the answer is yes, you shouldn't smoke or vape anything, cannabis included.

That's an act of peace and love for you and your future family.