Born with a passion of teaching and writing, Prof BN Chakravarty, still at age of 93 years, continues to teach and document information based on his own experience and contemporary scientific publications in his area of interest Reproductive medicine, infertility and assisted reproductive technology (ART). This volume (Volume 4) of the book bears plenty of such evidences.Apart from technologies like embryo transfer, mitochondrial transfer, vitrification, role of USG scan in reproductive medicine, the other interesting areas are interlinking fertility problems with commonly encountered endocrine, metabolic and some of the treatable oncologic disorders in young victims of reproducing age or even teenage boys and girls. PCOS and unexplained miscarriage are the constant and unavoidable trouble shooting areas for those clinicians who are involved with clinical practice of reproductive medicine. Chapters on these topics have also been included and elaborately discussed in this volume. The material and content of this book provide wide and rich information to the aspiring doctors and students who want to take up postdoctoral degree or specialise in the subspecialties of reproductive medicine and assisted reproductive technology.