Nazly - Does your DS have a way to go to sleep without you? Does he always have to have a fully tummy when being put down to sleep at bedtime and naptime?
If baby can just be placed into the cot when tired and he will go to sleep independently without any feed or intervention, then any night wakings would signal something that is wrong and needs to be resolved (it might just reassurance needed, to find comforter, maybe a drink, too cold, too hot, nappy change, pain etc.).
That's what you are aiming for, then you know that at 4.30am something is wrong and all you need to do is figure out what it is.
If baby needs you in some way when waking (either to physically be there to get to sleep, or feeding to give a fully tummy) then rather than focusing on that 4.30am wake up, I would focus my attention on getting to sleep at bedtime and naptime.
I find having a 'thing' that signals sleep is useful for wake ups. We have DD's dummy permanently attached to her sleeping bag and her blankies live only in the cot. So at bedtime as soon as we put her in the sleeping bag she looks for the dummy and going into 'sleep mode' even before in the cot. Then one in the cot, as soon as she grabs hold of blankie she snuggles it into her face and goes to sleep. This gives a trigger that can be used for any wake ups.
My DD usually stands if she wakes up in the night. So I can lie her back down (mimicking what happens at bedtime), give her the dummy if she doesn't already have it and snuggle blankie into her face. This is usually enough. I would then always know that if this doesn't work, something else is wrong.
At 4.30am I would consider a nappy change as reason for a wake up. That's just because DD drinks a lot during the day and her nappy gets full quickly. She hates lying in a full nappy. I would then consider temperature. If DD has been cool all night, by 4.30am she might be cold. Equally if she's been snuggly warm all night, she might be too hot by 4.30am. Failing that I'd try a feed.