Good afternoon, I would like to assist you today.
As the mother of twin 1 1/2 year old girls, I understand your situation, double-time.
That could be possible, how many naps was he taking before then?
Ans about what time does he eat, and lay down to bed for the night?
I'm sorry, I meant and
So, he sleeps at about 7 pm, and wakes up for the first time around 3 am, roughly?
Him sleeping from 7 pm until 3 am is already 8 hours; that's about as long as you can expect any infant his age to sleep at one time in the first place. Babies his age have small stomachs, especially if they are breastfed, they will wake earlier than that; my daughters, still breastfed, wake at least after 5 hours for a feeding; however the real problem here sounds like you getting him back to sleep.
I would try laying him down later than 7pm if possible; see if that helps. Is he bottle, or breastfed?
Breastfed babies very rarely sleep 8 hours or more at one time, that's almost amazing to me.
You have a great sleeper, overall
His naps are about an hour or two long?
Ok, so to clarify, he's now sleeping about 4 hours during the day, goes to bed at 7 pm, and wakes before 12; and then he doesn't get back to sleep, or when does he?
Well he's growing. These kinds of changes are very common throughout infancy. To be sure, it wouldn't be a bad idea to bring your son's sleep problems up to his pediatrician at his next visit; that will help rule out any health issues that may be the cause of this change.
Try waking him up before he wakes up screaming if possible. Give him his feeding, be sure he's dry and burped, and see if he can be laid back in his crib then.
Also, be sure that when he does wake in the middle of the night, or when you wake him, you keep him in a dim lit area, keep sounds low and voices down; too much noise or light could disturb his sleep. Soft music in the background has played in my girl's room since they were newborns. It helps to drown out any other household sounds wile they rest.
Yes, can you see my writing?
I will switch to the Q&A" format, and see if that helps.