I used protein soy protein drinks during my pregnancy for nauseau when food was too gross to think about and I also used it in addition to my meals (I worked full time and taught fitness classes). My doctor's knew I used them and didn't seem bothered by them but they also recommended products made by my vitamin company so I think that played a part in their support my drinking them.
On another note, my mom is a pediatric nurse and heard something at a seminar about using soy protein and it's affect on a male babies (as soy is usually something recommended for women) but she as she didn't have all her facts and the information she did have was preliminary - I took it with a grain of salt (I love my mommy though!).
Just some FYI.
jeni