The no-man's-land between reproductive physiology and immunology is becoming crowded. The last 10 years have seen a revolution in our under­ standing of many reproductive processes, brought about by the application of ever more sophisticated immunological methods. The increasing precision of these techniques has given us specific ways of assaying, enhancing or blocking hormonal mechanisms to yield more critical and interpretable information. In this volume eleven authors have presented the current status and future prospects of some immunological aspects of reproduction and fertility con­ trol. These include the relationships between mother and fetus, the diagnosis of pregnancy, the immunological complications seen in clinical management of human reproduction and some novel approaches for immunological control of fertility. We hope that in these chapters we have achieved an up-to-date account of a fast-moving field that calls on several disciplines. We intend the book to provide an adequate background and a current review for research workers and clinicians who wish both to understand the complex mechanisms involved and to develop improved scientific and clinical methods. We hope too that the student and newcomer will find this a useful reference book.