Training the next generation of obstetricians and gynecologists requires the provision of a strong foundation in the understanding of the basic science that underpins clinical practice. The MRCOG Part 1 examination has evolved to assess active participation of trainees in acquiring this fundamental scientific knowledge. The updated 2019 MRCOG syllabus and core curriculum acts as Scientific Platform for Clinical Practice, examining 15 core knowledge areas in four domains of understanding: Cell Function, Human Structure, Measurement and Manipulation and Understating Illness. Assessment has also been reformed to the format of single best answer (SBA) questions. This New edition has been updated with these adaptations to the MRCOG Part 1 examination in mind. We have brought in new editors and several new authors to update chapters. We have introduced a new chapter with self-assessment questions and answers, to reflect the revised examination format. We include 11 SBA questions per book chapter (17 for the anatomy chapter), and there mock exam papers. Included in this edition is a digital format to the book, to provide more flexibility in learning technique. We are grateful to the previous authors whose work formed the foundation of the current edition.