Manganese exposure and perinatal health: a systematic review of literature.

Manganese is essential for adequate feto-maternal health; however, an inverted U-shaped relation has been found between maternal manganese status and pregnancy complications. This systematic review summarizes the effect of maternal manganese exposure and perinatal health. We adopted a systematic approach to retrieve the recent literature. After applying the inclusion/exclusion criterion, a total of 20 studies were included in this review. Results found a non-significant relationship between maternal manganese exposure and risk of gestational diabetes mellitus (GDM), while only three studies reported the association between higher manganese levels and risk of preterm birth. Also, inconsistent results were found regarding higher manganese status and risk of low birth weight. This review reported no association between higher maternal manganese status andrisk of GDM. Nevertheless, the paucity of literature related to small for gestational age and pre-eclampsia prohibits a conclusion. Further studies are required for evaluation of environmental manganese exposure and maternal manganese status.