Comparative aspects of conceptus growth: a historical perspective.

This review provides a historical background for a series of articles arising from a symposium on Early Regulation of Mammalian Development. It begins by tracing connections between the work of J. Cossar Ewart and the first cloning of mammals by somatic cell nuclear transfer. Historical scientific landmarks over the last century that have affected our attitudes to 'fetal autonomy' and conceptus development are reviewed briefly, as are salient studies that have established the importance of nutrition to pre- and postnatal life. Finally, attention is drawn to some differences in conceptus development among various mammals, and the argument made that understanding these differences might be of benefit to the development of reproductive technology.