Movies, TV shows and advertisements seem to regularly float the hazy notion that smoking marijuana (AKA "weed") is harmless fun, but new research shows a woman's chance for delivering a healthy baby is actually what goes up in smoke if she lets smoke into her brain and lungs when pregnant.

Smoking Marijuana While Pregnant

Researchers from the University of Arizona looked at 24 studies of pregnancy and marijuana smoking. They discovered pregnant women who smoke cannabis were more likely to be anemic and their babies more likely to end up in neonatal intensive care units (NICUs) with low birth weights. If this isn't scary enough for you, you should also know that low birth weight is associated with lifelong intestinal and respiratory woes, brain bleeding and heart and vision problems.

Smoking Tobacco While Pregnant

This study comes at the same time that researchers in Leipzig's Helmholtz Centre for Environmental Research discovered tobacco smoking during pregnancy causes epigenetic disruption that dysregulates several genes at once. This means smoking during pregnancy, and likely secondhand smoke during pregnancy, causes an interruption in genetic material for baby and can trigger a long list of health problems for baby both as a newborn and throughout life.

Weed vs. Cigarettes

There is a lot of research showing that cannabis smoke is almost as toxic as tobacco smoke and can reduce levels of the neurotransmitter dopamine, impairing memory and making it hard to stop smoking without feeling depressed. Translation? If you're pregnant and you smoke marijuana, tobacco or both, or if you sit around for long periods of time with people who do, your dreams of a healthy baby may just go up in smoke.

Have other questions or need help with a smoking addiction? Talk to your doctor today - that's what we're here for.

This content originally appeared on Sharecare.com.