I'm experiencing this to my baby. She will start to sleep between 2AM to 4AM then only get 6-8hrs of sleep at night with an hour or 2hrs of waking up to breastfeed.
The 4 Month Sleep Regression at-a-glance:
A permanent change in how a baby sleeps.
Starts as early as 8 weeks and as late as 5 months.
Your baby now cycles in and out of sleep cycles, light and deep sleep, something he or she didn’t do as a newborn.
Your baby now wakes every 45 minutes to 2 hours.
Things never go back to what they once were.
While some babies will learn to sleep well after this change, many need your help learning how to sleep through the night or take longer naps.
Amabelle Mercado