A systematic review and meta-analysis of micronutrient intakes during pregnancy in developed countries

Micronutrient status during pregnancy influences maternal and fetal health, birth outcomes, and the risk of chronic disease in offspring. Research reporting dietary intake during pregnancy in nationally representative population samples, however, is limited. This review summarizes the micronutrient intakes of pregnant women from developed countries and compares them with relevant national recommendations. A systematic search without date limits was conducted. All studies reporting the micronutrient intakes of pregnant women were considered, irrespective of design. Two authors independently identified studies for inclusion and assessed methodological quality. Nutritional adequacy was summarized, with confounding factors considered. Meta-analysis data are reported for developed countries collectively, by geographical region, and by dietary methodology. Pregnant women in developed countries are at risk of suboptimal micronutrient intakes. Folate, iron, and vitamin D intakes were consistently below nutrient recommendations in each geographical region, and calcium intakes in Japan were below the Japanese recommendations and the average intake levels in other developed countries. Research examining the implications of potential nutrient insufficiency on maternal and offspring health outcomes is needed along with improvements in the quality of dietary intake reporting.