Freshly Baked Science
Why Do Babies Kick in The Womb?
17th January 2019
New life is amazing, isn’t it? A woman is able to grow a whole new human inside her womb in just 9 months’! It takes 9 months to create limbs, lungs, and a functional brain! But when you sprain your ankle it takes months to heal, yet you still feel it for years after. Anyway, there’s a special moment during pregnancy, that moment when the baby kicks. It’s a moment often shared with others; “Quick! Feel my belly, it’s kicking!”. A magical experience for sure, but why does it happen?
A fetus moves a lot in the womb, like crazy amounts. It starts as early as seven weeks, moving the neck, arms and legs, stretching, yawning, breathing, and opening their mouths. They do a lot in there, even sucking their thumb on occasion. These movements go largely unnoticed until the baby is about 18 weeks old… that’s when the fun begins. At 18 weeks the baby is a bit larger and stronger, able to make larger movements like kicks and punches.
A big reason for kicking and punching in the womb is not because they’re getting restless but because of health. That tiny human in there is growing at a speed you wouldn’t believe, all that moving around helps bones and joints to grow. Not enough movement can lead to some developmental problems such as brittle bones.
That’s not all though, a less obvious reason for all that moving is brain development! Upcoming theories suggest that all that moving around helps the baby to figure out their body. This was proposed by scientists who measured brain-waves of newborns, some of them were premature and represented babies that should’ve still be in the womb. When the babies were sleeping and kicking they found that the premature babies showed more activity in brain areas responsible for our senses, where we connect the feeling of stubbing your toe to the physical location of the toe. They concluded that when babies kick and hit a wall, they are providing their brain with a lot of information to learn about the body it’s in.
Imagine waking up strapped in a giant robot, buttons all around you. How do you figure out the controls? There’s no manual in the glove box, no YouTube tutorial, nothing. Naturally, you start pressing buttons, using controls, seeing what happens. After some time, you’ll get the hang of it, walking, running, punching, grabbing. That’s the situation for new brains as well, we don’t come with instructions. The brain has to learn how to control the body, what is connected to what, building a map of itself. Actually, it builds two maps of itself: one map representing what it can control and another mapping what it can feel.
Your brain has been shaped by your body to control your body, weird isn’t it? It has mapped out every sense and every muscle in order to move and feel what is around you. Changing your body means it has to do redo that mapping. Babies in the womb are still in this very early stage, where a rough body plan is being made. When they kick they feel the feedback from hitting the wall, which the brain can use to map out the body. This goes on for some time after they are born, especially the movement plan, but is especially strong in the last trimester of pregnancy.
Next time you high-five a baby by touching the mom’s belly, think about how you are helping it learn about itself. Doesn’t that make it even more amazing?