This book, written in 1971, was first published in Czech, in 1972. In the our years which have elapsed since then, perinatal medicine has made rapid progress, and new findings have been made in prevention, diagnosis and herapy. This meant that some chapters have had to be supplemented, corected or revised. Since Dr. K. Znamemicek, the author of several of the paediatric chapters and editor of the paediatric part of the book, died in 1973, his work as corrector and editor was taken over by Dr. K. Polacek, DrSc. n its main outlines, the English version is the same as the Czech, the only difference being the omission of parts specifically concerning Czechoslovak perinatological problems. We hope that the reception given to the English edition of this book will be as favourable as that received by its Czech counerpart.