Impact Of Maternal Pre-pregnancy Obesity On Placental Iron Transporter Protein Expression

Iron is an essential micronutrient for all living organisms and especially important in human pregnancy. Although essential, iron deficiency is the most common deficiency globally with pregnant women at an exceptionally high risk. Over 29.5% of women enter their third trimester of pregnancy with iron deficiency and 11% with iron deficiency anemia. This study sought to examine the impact of maternal pre-pregnancy obesity on placental transferrin receptor-1 (TfR-1) and ferroportin-1 (Fpn-1) protein expression. In this study we found that women with pre-pregnancy obesity had significantly lower TfR-1 protein expression and lower placental Fpn-1 protein expression. We also found a significantly lower ratio of placental TfR-1/Fpn-1 in women with low iron stores at delivery, suggesting a selfish placenta and hierarchy of needs within the maternal-placental-fetal unit. Our findings are notable, as recent studies have not found a significant difference in placental iron transporter protein expression in women who were obese pre-pregnancy. From a clinical and public health perspective, the take home message from this study is that women with pre-pregnancy obesity had lower expression of placental iron-trafficking proteins key to fetal iron transfer, and delivered neonates with lower cord iron markers. This is an important finding given the high prevalence of obesity among reproductive age women combined with evidence that even subtle changes to fetal and neonatal iron status can negatively affect neurocognitive development.