High Intake of Manganese During Second Trimester, Increases the Risk of Preterm Delivery: A Large Scale Cohort Study.

Evidence indicates that nutrients and minerals might play an important role in preterm delivery (PTD). The aim of this study was to determine maternal nutritional status during second trimester of pregnancy and its association with preterm delivery (<34 weeks gestation) in Iranian women. In a large scale longitudinal study, 1033 pregnant women were recruited from prenatal clinics since December 2012 to June 2013. Dietary intake was assessed by Food Frequency Questionnaire (FFQ) in pregnant women of 14 to 20 weeks gestational age. The participants were followed up until delivery. Dietary intake of women with preterm delivery was compared with women who had term delivery. The results show that 61.2% of women were primiparous and that the incidence of preterm delivery was 7%. Manganese dietary intake was significantly higher in mothers with preterm delivery than those with term delivery (P=.03). Manganese was the only micronutrient correlated with preterm delivery after adjustment for maternal characteristics during second trimesters of pregnancy (OR=1.12; P=.01). These results suggest that high maternal manganese dietary intake during the second trimester of pregnancy may be associated with the risk of preterm delivery in Iranian pregnant women.