Why do Babies Sleep So Much?

As a new parent, it’s normal to be concerned by how much and when your newborn sleeps. From the moment they are born, babies seem to spend the majority of their time sleeping, with some newborns sleeping up to 16-18 hours a day. While it may seem like an excessive amount of rest, it’s actually perfectly normal and necessary for your baby’s development. Why do babies sleep so much? What is happening in their tiny bodies that makes sleep such a priority? Let’s explore the science behind infant sleep during their first months of life.

Developing Sleep Cycles

Baby sleep cycles are very different from adult sleep cycles. Newborns have shorter sleep cycles and typically last about 50-60 minutes. These sleep cycles consist of two stages: rapid eye movement (REM) sleep and non-REM sleep. REM sleep, the stage where dreaming occurs, is particularly important for brain development. During REM sleep, babies’ brains are highly active processing and organizing information. As newborns grow, their sleep cycles gradually lengthen and become more similar to those of adults. In the first few months, however, their sleep is more fragmented.

The fragmented sleep is, in part, due to babies’ sleep patterns being tied to their feeding schedules. During the early months, babies’ need for nourishment every 2-4 hours can disrupt longer sleep times. Newborns need to feed frequently due to their small stomachs and high energy requirements. Sleep plays a crucial role in supporting this process. However, after they feed, they are often able to return to sleep and process the nutrients from the milk/formula.

Rapid Growth and Development

Sleep is an essential component of building a baby’s immune system. Sleep boosts the production of cytokines, which are proteins that help fight off infections, inflammation, and stress. As babies continue to grow and develop their immunity, they may require less sleep, but during the early stages of life, sleep is essential for helping them build a robust defense system. Newborns also use a significant amount of energy to perform basic physiological functions like digestion. Because babies have such a high metabolic rate and are in a constant state of growth, they require more rest than adults or even older children. 

One of the primary reasons babies sleep so much is the sheer amount of growth and development that occurs during their early months. They double in size during the first six months of life. Much of this takes place while they are sleeping. In the first year of a baby’s life, their little brains are developing rapidly.  New neural connections are being formed and sleep helps to consolidate memories and process the vast amounts of sensory input they experience throughout the day. Studies have shown that sleep is essential for the growth of new brain cells and the formation of synapses, which are the connections between brain cells that allow babies to learn and process information.

Furthermore, growth hormone secretion is significantly higher during sleep. This hormone is responsible for helping babies grow, not just in size, but in terms of muscle development and the maturation of their organs and systems. So, while your baby may seem to be in a constant state of slumber, their body is hard at work developing during these precious hours.

Conclusion

Babies sleep a lot because it is essential for their growth and development. During the long stretches of sleep, babies process information, learn new skills, and regulate their emotions. For new parents, it’s important to remember that the amount of sleep a baby needs varies depending on their age and individual needs. As your baby grows, their sleep patterns will evolve, but in the first few months of life, sleep is crucial for laying the foundation for their health. So, if you ever wonder why your baby seems to sleep all the time, know that they are simply doing the important work for the many milestones ahead.