She was described in the press as the "Baby of the Century." When Louise Brown, the world's first successful test tube baby, was born in Great Britain on July 25, 1978, the event was heralded as the beginning of a technological revolution in human reproduction. It was also the culmination of a decade-long effort, involving scientists on both sides of the Atlantic, to help a woman conceive through in vitro fertilization, or IVF. This is the story of two doctors - New York gynecologist Landrum Shettles and British physiologist Robert Edwards - whose work became the locus of debate over the limits of science and a precursor of the current debate over cloning and stem cell research.