Fetal phenotypic analysis.

Phenotypic analysis has been practised in many different ways, the most common being the recognition of normal and abnormal physical and biochemical characteristics and their patterns of inheritance. As different tools became available to analyze the characteristics of individuals the study of the phenotype and consequently of the genotype became more sophisticated. By the mid 1970's ultrasonography became a major tool in the analysis of human disease, and more recently it has contributed to the analysis of the human fetal phenotype in utero. This method, when used in conjunction with cytogenetic and biochemical analysis of the amniotic fluid, constitutes the main thrust of genetic prenatal diagnosis today. This paper describes and proposes the systematic use of ultrasonography, in conjunction with biochemical and cytogenetic tests to examine pregnancies at risk of congenital and inherited diseases and those that show signs of abnormality. We have examined 1500 fetuses and have detected conditions that affect only one system, like the skeletal dysplasias (osteogenesis imperfecta, thanatophoric dysplasia, diastrophic dwarfism, achondrogenesis I, Jeune syndrome and many others), neural tube defects, gastroschisis, multiple congenital malformations syndromes (Vater, Vacterl, Weyers olygodactyly, Meckel syndrome, and others). The analysis of the functionality of the fetus is one of the major achievements of genetic prenatal diagnosis by ultrasonography.