Parents of a newborn baby plus two other kids. I (32M) keep on inadvertently making my wife (31 F) mad/annoyed with me at night.

Married for 5 years. As the title says, we have two toddlers, plus a newborn. The baby is sleeping in our room currently in a bassinet. Baby needs to be changed, fed, and burped 2-3 times every night. As any parent knows, taking care of little kids (especially newborns) is extremely tiring and draining. I'm trying to help my wife any way that I can.Each evening, we'll elect who gets "first shift" and who gets "second shift" which is typically the first and second halves of the night for baby duty. The trouble we've been having is that when the baby stirs and needs something, I sleep through almost all fussing until she is legit crying. My wife is a light sleeper and practically leaps out of bed whenever the baby fusses before I'm aware of it. At that point, I'll offer my help, but my wife will be fully awake at that point and refuses help. This is mainly because when I wake up in the middle of the night, it takes me a few minutes for my brain to wake up. Making a bottle and staying alert enough to feed the baby while sitting in a dark room is difficult for me. One time I dozed off with the baby in my arms--not good.It seems like we go though the same cycle every night. Before going to bed we'll be upbeat and I'll offer to help with the baby. By morning, however, my wife will be upset with me because she will have done almost all of the work and gotten virtually no sleep while I slept through the night. I'm left clueless as to what I did wrong because I barely remember what happened.I've asked her to do a better job of awakening me, but she hasn't got much fight left in her after taking care of our other kids all day. During the day I'm at work or doing stuff on the house, so I really can't help there. Thankfully her parents are staying with us for a short time and they help during the day. I'm extremely thankful to have a wife that never nags me, but just this once, it'd be useful.How can I be a better husband overnight? A mom's perspective would be greatly appreciated.TL:DR: I sleep through the night and my wife ends up doing all the overnight work of caring for our newborn. I get sleep and she doesn't. I don't know how to help her more.EDIT: Thanks for all of the advice. I'm going to strongly suggest to my wife that she sleeps in a separate room from the baby when it's my shift. As long as she and the baby are in the same room she won't get proper rest. I'll find a way to make it work. via /r/Parenting http://ift.tt/2lU9lMA