You have a reduced schedule. The baby is FINALLY sleeping again and then WHAT! Suddenly not. Welcome to what's known as the 4-month sleep regression. Some might call this phase of heightened alertness, but it all boils down to the same thing: you and your baby recently found their line, and now the baby isn't behaving that way anymore.
You can check over here the (very common) sleep regression that is characterized by significant changes in your baby's behavior. Some of the 4 month sleep regression indicators are:
– Increased fear
– Frequent awakenings during the night (especially if the baby has just started sleeping longer at night)
– Reducing naps or "sleep disaster"
– Changes in appetite
Simply put, your baby's sleep schedule has just been reversed. This likely means your baby is growing. According to a study by various authors, your baby will be more engaged with the world around them.
When your baby realizes that they can interact with their world, they also begin to realize that their actions affect other people and they have a little more control over their environment. More often this sleep regression is associated with growth attacks.
You may find that your baby has outgrown his current wardrobe or his mobility has increased. Parents often don't understand why their cute baby is suddenly sleep deprived, cranky, moody and tired all night long.
You're wondering if it could be an ear infection, teething, a shortage of supplies – for nursing moms or maybe reflux, the list goes on. What parents often don't notice: Your baby's sleep rhythm also changes during this time.