Regression is a misleading term. My son started sleeping in my bed at around 5 days old and no he never regressed. At 4 months he did become more aware and his sleep patterns did become more consistent. My daughter was sleeping the first 80% of the night in the crib up to 6 months and the rest was in my bed. Her sleep patterns also changed at around 3.5 months but nothing serious. 6 months was rough though and I abandoned the crib completely.
4 months affected my girls naps but not night sleep. At 6 months she started waking for a feed again which she had dropped at 11 weeks. She is now 7.5 months and having split nights because screaming and raspberries are just too fun in the middle of the night 😅
I can honestly say I never noticed a difference in sleep and we coslept from birth to 15months
We had a 5 month regression occur even as a bedsharing / cosleeping family but my son started teething at 3 months so it was due to that more than anything I think
Around 4 months old is when babies enter “adult sleep”. I can’t remember the exact science but their sleep becomes more like ours with our multiple phases. Prior to 4 months, babies have 2 states: practically dead to the world sleep and awake 😜 Some babies struggle because they may need absolute darkness and extreme quiet, things like that. They may also need more comfort.
The only thing I noticed with each “regression” was my son would have a few more wake ups which I would give him a breastfeed and he would go straight back to sleep but nothing other then that. I have co slept with my boy from maybe a week old and he’s 18 months now and we are still sleeping in the same bed
As others have said, the sleep "regression" you're talking about isn't really *regression* because it's the result of the maturation of sleep processes. We've bedshared since about a week old and I didn't really notice much around the 4 month time. I think he started slightly rousing and nursing back to sleep a little more often at night, but I barely noticed because it was so easy to deal with it when he was sleeping right next to me. He's 8 months now and I think he's dropping a nap, which sometimes leads him to go to bed really late, but he still mostly sleeps okay. The biggest thing that interferes with his sleep is teething pain.
I’ve never experienced any sleep regression with my son. I’ve been lucky with my baby, since he has been sleeping through the night starting at 2 months sleeping by himself. At 2 1/2 months, I switched to co-sleeping and sharing a bed cause he started to cry at night and since then he has continued to sleep through the night.
We are 11 months and I can’t say that I have noticed a regression. She pretty much latched when she wanted. I was very aware of her moving so we just give her a stroke of the hair or something to reset her. Although I am currently going through split nights with her on the days that she’s trying to drop down to one nap.