Re: Ds in 9% weight ...what now?
I'd go ahead with all the tests to rule things out, but if they come back normal, then try not to worry, and try to push high calorie foods, like avocados.
As far as anecdata, my kids all tend to drop %tiles at about 9 months. My milk supply starts to tank, my period comes back, and they are usually crawling about. However, with #3, she was diagnosed FTT, but with no known cause. Between 6 and 12 months she didn't gain an ounce, and a few times she lost weight (went from 50% to off the chart). She also stopped meeting her milestones. It was really weird, because when a baby gets to the point that they don't meet their milestones from lack of nutrition, they are literally starving, and have odd head and chest measurements, and look like those commercials you see on TV for the adopt a kid thing. She looked great. She didn't get any longer, either, so she just looked like a cute chubby little 6 month old, with bright eyes, and a happy mood. Except she was 12 months old. She ate great. No one really knows what happened. They threw a diagnosis of CP at her, I think just to diagnose her with something, but they said that by the time she was 5 you wouldn't even notice. And that is really true. She's still thin for her age, she's 4.5 now and weighs 30 lbs, but she's pretty tall. She's still 6 months behind her peers, but at 4 it is barely noticeable. She's super healthy, smart, fun to be with, etc etc. She just stopped growing for some unknown reason.
Wife to my Navy doc, SAHM to 4 (11, 8, 5, 1)