Hormonal mechanism in reproduction. Biosynthesis and metabolism of different hormones in the fetal and placental compartments. Hormone production and concentrations during pregnancy in humans and in other mammalian species. Transfer of hormones between the fetal, placental and maternal compartments. Hormonal changes preceding paturition. Appendix I: The nomenclature, structure and physical properties of main pregnancy hormones. Appendix II: Trivial names and nomenclature of steroids used in this book. Index.