Babies kicking in the womb are creating a map of their bodies

Fetal kicks help to grow areas of the brain that deal with sensory input.


The first time a pregnant woman feels her baby kick can be surprising — a sudden reminder that the tiny creature growing inside her has a mind of its own. The baby kicks indicate that your baby is developing well inside the womb. You can understand that the baby is active when they turn, tumble, roll, and kick inside the womb.

A new study by the UCL in collaboration with UCLH suggests that when a baby kicks in the womb, it is creating a map of its own body. Moreover, kicking in womb enables baby to explore the surroundings.

For the study, quantified brainwaves produced when infants kick their limbs amid rapid eye movement (REM) sleep, finding that quick brainwaves – a brainwave design ordinarily found in neonates – fire in the corresponding hemisphere.

Almost 19 newborns aged two days on average were involved in the study. Corrected gestational age takes into account their age if they were still in the womb; a baby born at 35 weeks and being one week old would have a corrected gestational age of 36 weeks.

Scientists measured babies brainwaves using electroencephalography (EEG) and recorded continuously during sleep. Active sleep was identified behaviourally according to cot side observation of rapid eye movements, largely irregular breathing and frequent, isolated limb movements.

The findings suggest that fetal kicks in the late stages of pregnancy – the third trimester – help to grow areas of the brain that deal with sensory input, and are how the baby develops a sense of their own body. The fast brainwaves evoked by the movement disappear by the time babies are a few weeks old.

Study author Dr Lorenzo Fabrizi said, “Spontaneous movement and consequent feedback from the environment during the early developmental period are known to be necessary for proper brain mapping in animals such as rats. Here we showed that this may be true in humans too.”

“We think the findings have implications for providing the optimal hospital environment for infants born early so that they receive appropriate sensory input. For example, it is already routine for infants to be ‘nested’ in their cots – this allows them to ‘feel’ a surface when their limbs kick as if they were still inside the womb.”

“As the movements, we observed occur during sleep, our results support other studies which indicate that sleep should be protected in newborns, for example by minimizing the disturbance associated with necessary medical procedures.”

The study is published in the journal Scientific Reports.