BioDigest does have a few useful items, for background.
A search in Cambridge Scientific Abstracts Biological Sciences database turns up only a few hits for 'surrogacy', none of which is relevant to surrogate motherhood.
On the other hand, a search of PubMed is much more fruitful, with 103 hits for 'surrogacy'; the first question is whether we have any of the journals. And the answer, fortunately, is yes. But examining various full records can tell us various useful things, and often points toward other things (terms, sorts of literature) we should consider.
In the CSA version of MEDLINE, the DE:surrogate mothers produces 67 hits (in the 1992-1997 database)Since we have so few of the journals which deal in this topic, a reasoned and careful search will turn up a few likely candidates for InterLibrary Loan.In the PubMed version, a search for 'surrogate mothers' yields 345 hits, and the related articles utility can be very effective in focusing once we've found one that looks to be just right.