Structure and - Function -.- Embryology and physiopathology of early pregnancy trophoblast.- Fine structure of chorionic tissue in health and disease.- The enzymology of chorionic villi and the first trimester diagnosis of metabolic disorders.- Placental immunobiology in early pregnancy.- Transcervical Chorion - Villus Sampling -.- The method of chorion villus sampling under real-time ultrasound guidance using the 'Portex' cannula.- Transcervical chorion villus aspiration by a single operator technique.- Tipped metal cannulae.- The Nottingham brush for chorion villus sampling.- Chorion villus sampling using rigid forceps.- Blind chorion villus aspiration.- Ultrasound for transcervical chorion villus sampling.- Is ultrasound guidance necessary for successful transcervical chorion villus sampling?.- Endoscopic chorion villus sampling.- Danish experience.- Development and clinical application.- Clinical Applications.- Pregnancy outcome and the need for centralized data collection in chorion villus sampling.- Evaluation of the long-term consequences of chorion villus sampling.- Early prenatal diagnosis and therapeutic potentials for the fetus.- Early prenatal diagnosis and fetal surgery.- Towards a chorion villus sampling service.- Chorion villus sampling for direct chromosomal analysis in a non-teaching hospital.- The economic efficiency of prenatal screening.- Chromosomes and DNA - Analysis -.- Prenatal karyotyping: amniotic fluid cells or chorion villus samples?.- Chorionic villi and direct chromosome preparation.- Cytoculture of chorionic tissue.- Recombinant DNA technology and prenatal diagnosis.- Genetic engineering and detection of haemoglobinopathies.- Extraction of DNA from chorionic villi.- Genetic Counselling.- Counselling in prenatal diagnosis.-Chorion villus sampling in X-linked genetic disorders.