Hey, you don't need to know anything because you're nursing/going to nurse, right?

Wrong.

Because you might have to supplement (as I did ) and the formula you use could be a factor responsible for your child being allergic to dairy and soy (as my DD is) for many years of his/her early childhood (and possibly, gulp, forever.) DD is 3 years old, still nursing and has severe GERD and food allergies (to dairy and soy and peanuts.) She was supplemented with dairy and then soy formula from 4 days to six months, when she refused on her own to ever drink one more drop or take a bottle again.

Know there is formula with hydrolyzed proteins which is a better choice because it's more "hypoallergenic" than regular cow's milk or soy formula. Don't think "oh, they're all the same," because they aren't. Alimentum or Nutramigen is a safer choice if you HAVE to supplement. If you have a history of peanut allergy in your family or your DH's, there is NO WAY you should expose your baby to soy formula. I learned that the hard way.

And here's hoping GYou never do. I'd say the best prevention is going to LLL before your child is born, getting phone numbers and names and (just my opinion and experience) avoiding extraneous birth interventions if at all possible. Line up that support way before your baby arrives.