The book is devoted to one of the most important problems of obstetrics - the biomechanism of childbirth. It considers anatomical and physiological features and accompanying biochemical transformations of the reproductive apparatus, which are directly related to timely and untimely termination of pregnancy. Dynamics of changes during delivery of uterine contractile activity parameters, cervical opening, changes of its length are described, characteristics of fetal translational movement, birth canal shape, as well as variants and stages of separation of children's place in successive period are given.