The Association between Maternal Dietary Iron Intake during the First Trimester of Pregnancy with Pregnancy Outcomes and Pregnancy-Related Complications

Abstract

In this study, we investigated the associations of maternal dietary iron intake during the first trimester of pregnancy and pregnancy outcomes and related complications in pregnant women of Isfahan, Iran. In this prospective study, 812 healthy first-trimester singleton pregnant women were selected randomly from 20 various health centers across Isfahan city during 2015-2016. The maternal dietary iron classified into 2 groups, including heme and non-heme iron. Factors including pre-eclampsia, gestational hypertension, gestational diabetes mellitus, intrauterine growth restriction (IUGR), and nausea and vomiting in pregnancy considered as the pregnancy-related complications. Infant's birth weight, birth height, and birth head circumference were also determined as the pregnancy-outcomes. There was a significant association between total iron consumption and infant head circumference (p = 0.01). Total maternal iron (the sum of heme and non-heme iron) was negatively associated with both infant's birth height (p = 0.006) and birth weight (p = 0.02). Non-heme iron consumption is positively associated with high-risk of IUGR (p = 0.004). Heme intake was associated with an increased risk of maternal fasting blood sugar (FBS) (p = 0.04). Higher heme, non-heme, and total iron intake were associated with lower risk of pre-eclampsia (heme: crude p = 0.05; non-heme iron: adjusted p = 0.02; total iron: adjusted p = 0.05). Maternal total iron intake was directly associated with infant head circumference, whereas, negatively associated with both birth weight and birth height. High non-heme iron intake may increase the risk of IUGR, and a high intake of heme iron may increase FBS.

The association between dietary mineral intake and the risk of preeclampsia in Chinese pregnant women: a matched case–control study

“…A meta–analysis of magnesium intake and PE also showed that magnesium supplementation during pregnancy reduces the risk of PE (risk ratio [RR] = 0.54, 95%CI 0.59–0.98, P = 0.04) 43 . Our results for phosphorus 45 , iron 46 , manganese 47 and zinc 48 were similar to those obtained in previous studies. Hajianfar et al conducted a prospective cohort study to investigate the association between dietary iron intake during the first trimester of pregnancy and pregnancy outcomes 46 .…”

“…Our results for phosphorus 45 , iron 46 , manganese 47 and zinc 48 were similar to those obtained in previous studies. Hajianfar et al conducted a prospective cohort study to investigate the association between dietary iron intake during the first trimester of pregnancy and pregnancy outcomes 46 . The results of this study showed that higher haeme, non–haeme, and total iron intakes were associated with a lower risk of PE (haeme: crude P = 0.05; non–haeme iron: adjusted P = 0.02; total iron: adjusted P = 0.05).…”

Iron intake during pregnancy reduces low birth weight: A propensity score analysis

“…This controversial finding is dependent on the health status of the population studied. While the participants in this study were nearly healthy, their average total iron intake was higher than recommended 19 .…”

Iron Metabolism in Normal and Pathological Pregnancies and Fetal Consequences

“…The effect of iron supplementation on birth weight is still debated. For some authors, the risk of developing fetal growth restriction is associated with non-heme iron supplementation [158]. By contrast, others have found a higher risk of fetal growth restriction in cases of heme-iron intake [159].…”

“…During pregnancy, maternal iron intake has been shown to be directly associated with infant head circumference and negatively associated with birth weight and height [158]. The effect of iron supplementation on birth weight is still debated.…”