The plausibility of micronutrient deficiency in relationship to perinatal infection.

Infection has a major effect on adverse pregnancy outcomes, and this relationship appears strongest among populations that suffer from malnutrition. The most likely mediating factor linking this association is the effect of nutritional status on various host defense mechanisms. These mechanisms include intact skin and epithelial surfaces, phagocytosis by macrophages and neutrophils, cell-mediated protection by T cells and natural killer cells and antibody production by B cells. Deficiencies of virtually every vitamin and mineral and protein-energy malnutrition have been shown to negatively affect some or several host defense functions. There is therefore no question that a plausible relationship exists between micronutrient deficiency and infection-mediated adverse pregnancy outcomes. However, proof of this relationship is generally not available.