The ninth edition of Before We Are Born has been completely updated to reflect current understanding of clinical human embryology. It provides the essentials of normal and abnormal development. As in earlier editions, clinically oriented materials are highlighted in blue color (often called blue boxes). Every chapter has been revised thoroughly to reflect new research findings and their clinical significance, as well as new understanding of the developmental biology. This edition follows the official international list of embryological terms (Terminologia Embryonica, 2013). It is important that physicians, nurses, physician assistants, dentists, physical and occupational therapists, other health professionals, scientists, and students in the health professions throughout the world use the same name for each structure. We have included numerous new color photographs of embryos, fetuses (normal and abnormal), neonates (newborns), and children. There are also many new diagnostic images: US (ultrasound), CT (computed tomography) scans, and MRI (magnetic resonance imaging) studies of embryos and fetuses. An important feature of this book is the Clinically Oriented Questions, which appear at the end of each chapter. In addition, available through Elsevier’s studentconsult.com website, there are many helpful clinical case studies and questions with answers and explanations. These will benefit students preparing for USMLE Step 1 and similar examinations. Accompanying this ninth edition of Before We Are Born is an innovative set of 17 fullcolor animations that will assist students in learning the complexities of embryologic development. These animations are available at studentconsult.com. High-resolution animations are available to teachers for their lectures if they have adopted this book or The Developing Human (consult your Elsevier representative).