Whole embryo culture, teratogenesis, and the estimation of teratologic risk.

Mammalian whole-embryo culture systems are now widely used and have proved useful in many studies of normal and abnormal development. The main advantages of these systems are that they allow precise control of experimental conditions and can often provide information unobtainable from in vivo studies; the main disadvantages are the rather short period of embryonic development that can be supported in culture and the present restriction of the techniques to very few species. The possibility of using whole-embryo culture systems for screening for new teratogenic agents remains controversial, but there are indications that the systems may have more potential in this area than has sometimes been supposed.