Over the years, our team has seen countless parents come to us for help with their 4 month old babies sleep. Why? Simple - it's the 4 month sleep regression. This article will explain why "good" sleepers sometimes turn "bad" around the 4 month old mark, also known as the 4 month sleep regression. For most babies, the 4 month sleep regression occurs right around the 4 month mark, but for some babies, it happens a bit earlier (around 3 months) or a bit later (around 5 months). For some babies, the