In the four years since the publication of the third edition, this book has been very well received by those for whom it was intended - candidates for primary examinations in Obstetrics and Gynaecology. In consequence, we make no excuse for repeating the formula of addressing only those facts which are neither speculative nor contentious. An attempt to widen this brief would multiply the length of the book by three or four times and would place it in an identical category with several much larger texts. As the underlying philosophy remains the same, the main changes in the fourth edition are the addition of new material and revision of existing material. Revision of existing material has been extensive with many detailed changes aimed at expanding the factual base while retaining or improving the clarity of explanation. In addition, the book is now associated with an MCQ Tutor which has proved especially popular. Finally, and probably most importantly, many of the changes are those which have been suggested by readers and reviewers of the previous editions; this feedback has been invaluable to the authors and we now hope will be equally valuable to readers of the new edition. In this edition we wish to express our particular gratitude to Dr John Clark and Miss Lois Hague for the very elegant new illustrations in Chapter 2.
