Improving prenatal nutrition in developing countries: strategies, prospects, and challenges.

In developing countries, the health and nutrition of females throughout their entire life is affected by complex and highly interrelated biological, social, cultural, and health service-related factors. Rather than focusing exclusively on the prenatal period, we describe a life cycle approach to improving maternal nutrition, which goes beyond the traditional provision of nutrition services during pregnancy, by addressing risk factors that are present well before pregnancy, even before childbearing age. This approach involves specific policy initiatives and a "minimum package" program that is targeted at females. Policy actions and the components for effective implementation of the program are described. The prospects and challenges to be overcome-which include translating scientific knowledge into action, removing conceptual and implementational constraints, identifying biologically meaningful indicators for problem identification, and improving understanding of physiologic and social adaptation mechanisms-are discussed, as are persistent problems with health care delivery systems.