The little problem = Birdie dropped on her growth curve for length and head circumference a little bit this (9 month) visit and a little bit at the last (6 month) visit.
The bigger problem = Birdie LOST 5oz. between her 6 and 9 month visits and dropped "significantly" on her growth curve at this visit (multiple lines.)
Developmentally and cognitively, she's doing great. She crawls, climbs, stands, cruises, waves, babbles... she's perfect. She even looks perfectly average ("sturdy" even, lol.) The problem, as I had to explain to poor P (who looked bewildered and a bit defensive when I told him about this) isn't how much she weighs - she's not underweight for her age or height - it's that she lost weight in the first place and that she's no longer gaining at a pattern normal for her.
So what they look at first is intake/output of nutrients. Birdie is still breastfeeding normally, at an average of 9 times per day. She has begun to take some solids and some water from a cup, but not enough to decrease her intake of breastmilk, which is good. She is having a good number of wet diapers per day, so we know she's getting enough milk. There are no obvious problems here.
Which brings us to where we are now. Since there's no sign as to what the problem might be, they look at blood and urine to see if there are any clues. If she has an illness (like a chronic UTI, for example) her body may be expending more calories to fight the infection than she's taking in, even if she's taking in a "normal" amount. This could be a little thing, easily fixed, and that's what we're hoping for. There are other possibilities, like hormonal issues, that can also factor in.
I won't say it's the "worst" thing, because I know there are many, many worse things out there (and have imagined them already, thanks,) but I'm NOT hoping that the blood panel/urinalysis reveals nothing. Because then we're back to she's losing weight and we don't know why.
I'm taking her to Children's for bloodwork tomorrow and hopefully I'll be able to get a urine sample from her to take that in with us.
In the meantime, thank you all for your kind words and thoughts.