Why Do Babies Smile While Sleeping?

Why Do Babies Smile While Sleeping?

Medically Reviewed By
Dr. Arti Sharma (Paediatrician)
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It is common for babies to smile or laugh when they are awake. But they also smile while sleeping. If you have recently given birth to your baby and watched him sleeping for hours, you must have noticed a twitch or smile on his face, and it must have been a sight to behold! But why does a baby smile while sleeping? Find out!

Video : Why Do Babies Smile in Their Sleep?

Why Do Babies Smile or Laugh While Sleeping?

 A baby boy smiling while asleep.

Many people think that babies see angels while sleeping, and this is why they smile. But that may not be true – as there is not much scientific evidence available. Babies are likely to smile or laugh in their sleep because of one (or more) of the following reasons.

1. Developing Emotions

While awake, little ones are exposed to new sounds and sights. During this time, their developing brains may tend to record all the daily experiences and information coming their way, which possibly gets processed while they are asleep. The happy emotions felt while dealing with the new knowledge and their understanding of it may get exhibited through smiles or laughter in their sleep. Hence, smiling or laughing while asleep can be a part of the process of evolving emotions in babies.

2. Passing Gas

It is believed that babies start displaying social smiles once they turn 3-4 months old. But if a baby smiles in the first few weeks of his birth, it may infer that he is probably passing gas. This notion is however not supported by any concrete scientific research. Nevertheless, it is a known fact that colic babies tend to remain irritable, and farting brings relief and helps them feel better. So one of the reasons for smiling during sleeping could be that the baby is passing gas.

3. REM Sleep Cycle

While in the REM sleep he can experience certain physiological changes that trigger some reflexes and one of them may be a smile. REM sleep phase may also result in rapid eye movements (REMs) and vivid dreams. In case you happen to notice your baby smiling or laughing in his sleep he may quite possibly be in the REM sleep cycle, recalling some funny episode that occurred earlier in the day.

4. Other Medical Causes

In rare cases, convulsions and fits may manifest as unceasing laughter. If you notice other symptoms such as weight loss, trouble while sleeping, frequent bouts of irritability in him, or laughing for no apparent reason, you must take him to a doctor immediately. The occurrence of convulsive laughter episodes can disrupt your baby’s resting schedule, thus negatively impacting his health.

Different Types of Smiles in Infants

By now you know why a baby smiles during sleeping. It could be because of developing emotions, the REM sleep cycle, or perhaps some medical issues. But did you know there are different types of smiles too? Yes, babies have different types of smiles, which have different meanings. And all these smiles are important milestones of their lives. If a newborn baby smiles in his sleep, his smile can be of three different types and they mean the following:

1. Social Smile

Babies are likely to go through many emotional changes in the first few years of their life. As they slowly grow up, they may become more responsive, alert, and interact with other people. Babies between 3 and 4 months of age, often break into social smiles as a reaction to the attention and gestures of the mother.

If your baby has developed a social smile, it is an important developmental milestone and is indicative of intentional expression of warmth towards you. It means that your baby is bonding with you. When a baby shows a social smile, it could be a sign of brain development in him. It also means that the baby’s communication skills are advancing. At this point, you may want to interact even more with your baby by way of cuddling, making comical faces or even simply talking to him to increase more instances of social smiles of your baby.

2. Reflexive Smile

Babies also demonstrate fleeting smiles while sleeping, especially within the first few days of their birth. Experts are of the opinion that these episodes of early smiles in babies are reflex actions similar to other reflexes shown by newborn babies like sucking and rooting. Reflexive smiles while sleeping are supposed to be innate gestures. They do not have an emotional trigger but are usually nature’s way for a baby to begin practising different skills. In fact, reflex smiles may happen while the baby is in his mother’s womb from 25 to 27 weeks of gestation. After birth, reflexive smiles may typically occur during the REM sleep phase.

3. Responsive Smile

Responsive smiles may manifest around 6 to 8 weeks of baby’s birth. A responsive smile while sleeping maybe a baby’s response to sensory experiences or things he finds enjoyable like a familiar soothing voice, cuddles, etc. Responsive smiles are not social reactions but simply a reciprocating action subject to what a baby senses. Responsive smiles can help you learn about your baby’s likes and dislikes, what amuses him or what can make him grin.

Watching an infant smiling while sleeping is not only heartwarming but an important sign that the baby is developing emotionally and physically. It is essential for parents to understand that different babies can have varied learning curves and developmental milestones. So they should not unnecessarily fret in case their baby doesn’t display certain milestones. Let your baby develop at his own pace and enjoy the little moments with him.

Also Read:

When Do Babies Smile & Laugh
30 Cute Baby Smiling Photos

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