3.5 years is still young, meaning LOTS of kids this age are still going through this. It's okay.
Remember, their bladders are tiny too. Be sure to not put too high expectations on him or pressure. Night time dryness, 100% of the time does not happen perfectly.It's okay. My daughter, now 5 years old, still has occasional accidents at night still. Over the past year, is when she finally stopped wearing the night time diapers. Also, when they sleep so soundly...they don't always wake up to go to the toilet. It's okay.
What I do is put a waterproof bed pad under her when she sleeps, THEN, if there is an accident, it is easier to clean up as I don't have to wash the entire bedding set. If she does have an accident, we just go about cleaning it up, yes, in the middle of the night, but don't make it emotional or confrontational or embarrassing for her. All kids have accidents, even when they are much older. So, for your question as to whether they will "grow out of it"... well, yes and no. They do get better at night time dryness, but they will have accidents sometimes too. I even know a friend's child who is 7, and he still has accidents once in a while.
Also, children do not have full 100% "impulse control" yet...so keep that in mind. Yes, some kids do better than others. But each child is different.
He will get better at night time control sooner or later. He is still young. You can always check with your Pediatrician to make sure he doesn't have any bladder problems, "immature bladder" kind of thing. But I would just chalk it up to he is still "transitioning" to night time control ability. Transitions can take time. It's okay. It's great he has daytime control. Hooray for the little guy. :) I hope my 19 month old son will be that way... he already "tells" me when he has to pee, but have decided not to "rush" him to full potty training yet.
Oh, there are also "training pants" that perhaps you can use, instead of "diapers" which may be more comfortable for him. They are usually cloth, with a built-in "pad" to absorb the pee etc. But yes, it is washable, waterproof and leak proof. You can even find them on E-bay for cheaper in multi-packs. Just type in the search word "training pants." I got my son these and it's great.
Congrats on your soon to be baby! How wonderful!
Good luck and just wanted to share what I've known and gone through with a now older child.
~Susan
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