my skinny baby- 5 months

Chris had a doctor's appointment today for followup of his poor weight gain. He was 12 lb 8.5 oz today, up 1.5 oz from last week. Babies his age should gain 1/2 to 1 ounce per day, and he is not meeting that. We saw Dr. Cain again, who is the chair of Family Medicine at Children's, and I trust his judgement. Based on history and physical exam, Chris has no problems with his GI tract or his heart that would cause poor weight gain. I think he is nursing better thanks to the tips from Marianne. The doc thinks that Chris is small but active and healthy, and reassured me. He thinks that Chris may just end up being a small child and/or a small adult. I'm small, and Doug is average size. Chris will go back for another weight check in two weeks, and if he's still not gaining weight appropriately, he will get a Pediatric Endocrinology referral. Chris' weight today was down to the 1st percentile. 99% of babies his age are heavier than he is. He is 24.5 inches long, up one inch from last month, and his head circumference is 45 cm.