I DOUBT THAT ten years from now sessions like this will be held on the subject of "pregnancy wastage." The challenge is less that of salvaging waste than of developing a prenatal public health. There are at least three reasonable objectives of this public health of pregnancy: to reach demographic equilibrium before it is forced on future generations by famine or the mass slaughter of war; to understand and adapt to genetic laws; and to control adverse environmental factors that may cripple our descendants before they Ire born. For over a century thoughtful scientists, such as Geoffrey St. Hilaire, Camille Dareste, Charles Stockard, Franklin Mall and many others, labored to gain that practical understanding of the origin of acquired deformities which in part is ours today. One discovery after another has come tumbling out of the field and the laboratory since the role of German measles in causing congenital anomalies of the infant was first detected in Australia. Yet we are still far from that theoretical and practical knowledge which is necessary before tangible and effective measures can be developed to improve the health at birth of future citizens. Almost two decades after the teratogenic effect of maternal rubella was established, the indications are that there is more, not less, rubella among young adults and, hence, among young mothers. Many other infections have not even had cursory evaluation. No one can say, for example, whether or not the 1957 Asian influenza has left an impact on many lives then unborn. Realization that most congenital defects may have their genesis during prenatal life and may be preventable is of recent origin. The idea is an old one, but today's proof that controllable maternal illness may distort fetal development stems in most part from clinical observations made all over the world in the 1940's concerning the impact of German measles on the conceptus when the infection is acquired by the mother during the first trimester of pregnancy. Epidemiologic confirmation was slow because of the impossibility of observing abnormalities develop in utero after a specified maternal-fetal disorder. Case finding was the bottleneck, for postrubella congenital defects cannot be diagnosed until birth, at the earliest; for years after birth, as with hydronephrosis; or perhaps not until autopsy, as with aneurisms of the circle of Willis. Not only are the clinical manifestations of deforming disease in the embryo or fetus hidden from view, but the final pathological consequences seem to be of relatively nonspecific nature. For example, congenital cataract, deafness, heart disease, and dental defects are not pathognomonic of rubella. To be sure, they frequently occur as lifelong marks