Baby Proof.(Brief article)(Book review)

Baby Proof EMILY GIFFIN. St. Martin's, $23.95 (352p) ISBN 0-312-34864-9

The bestselling author of Something Borrowed and Something Blue now tells the story of what happens after the "I do"s. As a successful editor at a Manhattan publishing house, Claudia Parr counts herself fortunate to meet and marry Ben, a man who claims to be a nonbreeding career-firster like she is. The couple's early married years go smoothly, but then Ben's biological clock starts to tick. A baby's a deal breaker for Claudia, so she moves out and bunks with her college roommate Jess (a 35-year-old blonde goddess …