In developing countries, most cases of LBW are attributed to intrauterine growth retardation (IUGR) rather than to preterm delivery. Factors interacting with fetal development are numerous. Among them maternal malnutrition, particularly energy and micronutrient deficiencies, and malaria during pregnancy are assumed to be major determinants of IUGR. Dietary surveys have consistently shown that multiple micronutrient deficiencies, rather than single deficiencies, are common. However, a number of randomized clinical trials in various countries have shown only a modest beneficial effect on fetal growth when providing multiple micronutrient supplements during pregnancy compared to folic acid and iron supplementation. It is expected that chronic energy deficiency during pregnancy could be hampering the full potential of the effect of multiple micronutrient supplementation. Therefore it is expected that incorporating multiple micronutrients in a food supplement (FS), that provides supplementary energy and protein, instead of multiple micronutrients (UNIMMAP), could have an effect of public health importance on fetal growth and its correlates. The UNIMMAP supplement composition, incorporated in the FS or given in the form of a tablet, was proposed by an expert committee organized by UNICEF, WHO and UNU for pregnancy and lactating women.