Quoting Funny Feminist:" Hey, my son was born teeny tiny (4 pounds 15 ounces at full term) and had issues latching because of ... [snip!] ... Anyone else that pumps exclusively or did? I am getting frustrated with my let down and do not want him to move to formula."
Hey, one of my twins was the same size (but 5.5 weeks early). We had a lot of problems with latching and ended up getting it to work with a nipple shield. Then when I tried to ween off of it (because it was a pain), they still couldn't latch effectively enough to fill up. I ended up giving up on bf after 5 weeks and exclusively pumped (this way others could help me with feeding the girls). It is def hard! I did it for 5.5 months. I was able to exclusively give them breastmilk, but I pumped every 3 hours. Apparently it helps if you can pump in front of your baby. Also I ended up getting a prescription for domperidone (avail only in canada maybe) that helped increase my supply when I fell a bit short. My babies didn't seem to mind an ounce or so of formula mixed with breastmilk if I had to top them up once in a while.