Key Points The heart is largely derived from mesoderm. A single heart tube forms with venous and arterial connections. It elongates by addition of cells at either end from the surrounding mesenchyme. The tube folds to the right and lies…
Key Points Pathological examination of the placenta may provide useful information regarding the underlying mechanisms of a range of pregnancy complications that may guide future management and improve understanding of disease pathophysiology. Placentas should be submitted for examination by specialist…
Key Points Maternofetal exchange across the placenta provides the solutes and water needed for fetal development and growth and enables the waste products of fetal metabolism to be transferred to the maternal circulation. The placental exchange barrier consists of the…
Key Points The development and structure of the human haemochorial placenta The development of the uteroplacental and fetoplacental circulations Introduction This chapter highlights areas in which developmental placental biology directly impinges on clinical practice. Pregnancies complicated by the pathologies of…
Key Points The extravillous pathway of trophoblast differentiation is essential for the development of the fetoplacental blood supply. As they invade into the maternal decidua, extravillous trophoblast cells express a unique array of human leukocyte antigen (HLA) class I molecules,…
Key Points Miscarriage and ectopic pregnancy are the commonest early pregnancy complications. The diagnosis of early pregnancy failure should be made on transvaginal ultrasound scan given its high diagnostic sensitivity and specificity. Sporadic chromosomal abnormalities are the overriding cause of…
Key Points At baseline, each pregnancy has a 2% to 4% risk for a congenital anomaly diagnosed at birth. The adverse effects of exposures on embryo-fetal development depend on the agent, dose, and timing of exposure. Resources are available for…
Key Points This chapter presents the concepts and timing of embryonic development. The problems of using staging systems to describe a continuous process are discussed. The method behind staging of animal development is presented. A revision of the timing of…
Key Points This chapter describes the tissue types present in early embryos and the interactions between these tissues. The membrane systems and cytoskeletal elements within a typical cell are reviewed. Early embryos contain only epithelial and mesenchymal populations. Each tissue…
Key Points This chapter considers the language used within embryological research and how it is evolving. The terms used to describe embryos, cells and tissues derive from the social constructs of science during the time they were created. Newer terms…