NOTE: For more on today's subject, see my essay, " Genetic Medicine: Ethical Imperatives and Challenges ," on our website. On July 25, 1978, Lesley and John Brown of Oldham, England brought their first child into the world, a little girl named Louise Joy. Why is the world remembering Louise on her birthday? Because she was the world's first "test-tube" baby. Actually, she was conceived in a Petri dish through a process that came to be known as "in-vitro fertilization" (IVF). Her mother had blocked fallopian tubes, so doctors united her egg with her husband's sperm to produce an embryo, which they then implanted in her womb. The process was experimental 37 years ago; more than five million couples have since conceived children in this way. Since infertility affects 7.3 million people in the U.S., or one in eight couples, assisted reproductive technology (ART) is a tremendous medical advance. It raises enormous ethical questions , h