The purpose of this review was to determine whether routine administration of iron and vitamins during pregnancy had beneficial effects on birth weight, length of gestation, infant morbidity and mortality, and maternal morbidity and mortality. We searched for controlled clinical trials done in developed Western countries and reported in English, German, Finnish, and Scandinavian languages. Seventeen trials were found. In one trial, women who received vitamin B6 developed less dental caries. In another trial women receiving several different minerals and vitamins ahd fewer deliveries before the 40th week and less pre-eclampsia. In a third study, women receiving polyvitamin concentrate had less pre-eclampsia. None of the studies reported and benefit for other outcomes.