how do you know if they're getting enough (still hungry)?

julieruns15

My LO (4.5 weeks) is gaining weight but not as much/fast enough as our pediatrician would like. He advised supplementing with pumped breast milk (2-3 times per day) and /or formula IF pumping extra was too much for me. Well, I have been having some Post Partum Anxiety/Insomnia issues so I'm only able to pump one extra time per day. Now that I'm feeling better and on medication, when I pump for 10 minutes I get 2-3 oz. I've been giving that back to the baby in a bottle and then do 2 oz of formula once or twice per day. Nursing takes a LONG time (anywhere from 30-60 minutes) which is fine by me, it's relaxing, but LO gets lazy and falls asleep, loses his latch, etc. Sometimes, I feel like he gets a really good feeding, other times, I have no idea and obviously I worry. I do think he wasn't getting enough hind milk before but I have since gotten some pointers that I think are helping. I try to offer him some extra milk after a feeding but he doesn't seem interested in the bottle half the time (even if given by Dad). Does this mean he's full? He doesn't cry or fuss at feedings, afterwards he's usually happy and playful...even if he fell asleep I can wake him up for some playtime... thoughts? Advice?