We thank our wives, Joan, Aileen, and Sara, for their support, understanding, and patience with our lifelong commitment to the care of babies. We further thank our colleagues, who have agreed to share their knowledge and experience and have helped to ensure that there will be others like them who will know even more than they do and will be better able to apply what they know. Finally, we thank Lisa, Cele, and Ana for their careful scrutiny of our editorial efforts and all things administrative, and we also thank our many residents and fellows, whose intellect and enthusiasm have continued to inspire us.