You might have heard it a few times during your pregnancy: happy moms make happy babies. It might seem a little far-fetched, but studies have proven that there is actually something to it.

A study published in the journal JAMA Psychiatry explains that depression in pregnant women can have an effect on their unborn babies.

There are a few ways serious stress and "the blues" can affect your unborn baby's mental and physiological development...

Babies born to depressed mothers were about 1.5 times more likely to experience depression by the age of 18 than those who were not.

While many women experience surges of emotion from the normal hormonal changes of pregnancy, the more serious symptoms of depression can actually have an effect on their developing babies.

The Baby Blues

The changes of pregnancy can be stressful at times. A mother who generally bounces back after each up and down doesn't have to worry about the occasional stressful moment doing much to affect their growing baby.

Anxiety & Depression

Long-term anxiety has been proven to affect the fetuses mental development.

One study found that if the mother is in the top 15% of the population for symptoms of anxiety, her child (at 13 years old) is about 12% likely to have emotional or behavioral problems.

Researchers have found that the physiological consequences of depression that a mother experiences can be passed through the placenta and influence the development of the fetus' brain.

Cortisol & The Brain

The different ways, and just how much a child is affected by the mother's stress, depend partly on the baby's genetic makeup.

Long-term, the mother's mood can affect how the placenta functions. If she is highly anxious, there is less of the enzyme that breaks down cortisol.

Exposure to higher levels of cortisol (a stress hormone) in the womb can affect the way certain genes are switched on or off. This could lead to the development of depression, anxiety disorders, and ADHD.

Other Factors

The good news is that how we turn out depends on how our genes interact with our environment - both in the womb and outside of it.

Parents can still do things to influence how a child develops. A supportive partner can buffer the pregnant mother and baby against the effects of anxiety and depression.

A pregnant woman who suspects she might be suffering from something more than mood swings can reach out to her health care professional. Non-medicinal therapy like Cognitive Behavior Therapy can be helpful in navigating depression during pregnancy.

Finally, the human brain is plastic, which means it is open to change - especially in infancy and our early childhood.

The quality and sensitivity of care after birth can dampen the effects of anxious programming that happens before a baby is born.

[h/t CureJoy / Spectator Health / PubMed]