I certainly had second thoughts about prophylactic use of hydrolysates
after reading the abstract of this article:

Rigo J, Salle BL, Picaud, JC, Senterre J:  Nutritional evaluation of
protein hydrolysate formulas.  Eur J Clin Nutr. 49Suppl(1): S26-38, 1995.

Abstract is excerpted below, full text of abstract available on Medline:


Cindy Turner-Maffei, MA, IBCLC
WIC Nutritionist & Lactation Consultant, Cape Cod, MA, USA [log in to unmask]

> In conclusion, these studies provide evidence
> that protein hydrolysed formulas are not equivalent to whole protein
> formulas in terms of nutritional efficiency for preterm and term infants.
> Therefore further extensive nutritional studies on growth, biochemical
> indices of protein metabolism and metabolic balance, including minerals
> and trace elements, appear to be necessary before maintaining and
> promoting the use of such formulas for teh [sic] potential benefits on atopic
> disease in preterm and in full-term newborn infants.-- Rigo, J, cite
>above.