I have a 19 month DS. My hubby and I are starting to think about having number 2. I'm really struggling with the decision, as I had PND with first that has only just eased off. The worst part of my PND was severe anxiety if DS woke in the night. He actually sleeps brilliantly and has only woken up in the night about 7 times since he's been sleeping through so I am very lucky.
I'm wondering whether a new baby would wake my DS up in the night when he/she arrives? DS would be in a seperate room, but he sleeps so well at the moment, I'm terrified that a new baby who is waking and crying in the night would disturb him.
I was amazed that my eldest slept through all but the worst of the newborn baby cries. Even now that they share a room (2yrs and 1yr) they don't wake each other when one is unsettled. I expected it to be an issue but it hasn't been at all.
its generally not a problem at night unless DD is really going for it but daytime naps can be disturbed. If DS (2yo) is playing loudly or throws something it can wake DD but she is usually settle-able unless she was going to wake up soon anyway. Is they are napping at the same time and DD wakes first she will often wake DS and he is harder to settle back if he has had 1 hr. It does happen but they are surprisingly tolerant
Agree with Trixie, the issue when you have 2 DC is usually more about how to keep the older DC from waking the baby (IME) and not the other way around. If your older DC is a good sleeper and now in a regular routine, I wouldn't expect that to change much, apart from the usual things which always disrupt sleep - illness, travel etc.
Having had 2 DC myself, I would advise that, whilst it's brilliant seeing them interact, and I can't wait to watch their relationship gradually unfold, things can sometimes be very chaotic, loud, disruptive and stressful! Especially at the start until you get more used to handling two. Or at least it can be in our household, it may not be in yours but there's a chance, so you need to feel you could cope with both crying at the same time, or one crying/playing and preventing the other from sleeping...being able to go with the flow a bit is necessary round here with two dc.
But i would definitely say that the sleep thing has been much more the other way for us and we have just had to accept that the baby doesn't always get the sleep she wants/needs - that's just life with an older 3yo dc in the household, and friends in the same boat say the same thing. The first born is always lucky, they get the silent house where they can sleep peacefully. Subsequent children have to put up with a lot more noise! I would make sure you're ok with the thought of this side of things (although to be honest i didn't realise it until i had the second...)