The 20th century saw profound changes in obstetrics, and since the publication of the first edition of Williams Obstetrics in 1903, these changes have been continuously reflected in it in chronological order. We think it is worth recalling the preface written to the first edition of this textbook by John Williams and assessing whether its original purpose still holds true today:

"In the following pages I have attempted to set forth in depth the scientific basis of the practical application of the art of midwifery. At the same time, I have tried to present the aspects of midwifery with a practical focus in such a way that they are of immediate service to the midwife at the patient's bedside.''

We hope that readers of this 20th edition will find that the authors have worked in the spirit of the original principles laid down by Williams and expressed in the following key phrases from the preface to the first edition:

Thoroughness
Scientific basis
Practical application
The obstetrician at the bedside the patient