When you find protein on the stick, look at the specific gravity too. Highly concentrated urine can give you a false positive. (I'm sure you know that....but I'm saying this to those who may read this and not know.)
The standard response to protienuria is to intake more protein. I think kidney support would be effective. Cut out caffeine and other things that stress the kidneys. (I'm not sure if other midwives give that advice but it seems like common sense to me.)
:)