Maternal and Neonatal Iron Status Impact the Expression of the Heme Transporter, FLVCR, in the Placenta

Abstract

Mechanisms of placental heme iron transport are largely unknown. To address this, expression of the heme transporter Feline Leukemia Virus, Subgroup C, Receptor (FLVCR) was measured in placental tissue from 84 pregnant teens (13–18 y). Iron (Fe) status indicators, serum ferritin (SF) and serum transferrin receptor (sTfR), were measured at mid‐gestation (25.1±3.5 wks) and in maternal/cord blood at delivery (39.8±1.1 wks). At delivery, 33% (18/54) of teens were anemic (Hb<11 g/dL); hemoglobin (Hb) averaged 11.6±1.5 g/dL (n=54). Maternal SF at delivery was 21.8±13.3 μg/L (n=67); 52% (35/67) had depleted Fe stores (SF<20 μg/L). Neonatal SF averaged 140.8±79.9 μg/L (n=65). At delivery, maternal and neonatal sTfR averaged 5.8±3.7 mg/L (n=66) and 8.0±2.4 mg/L (n=65), respectively. A significant relationship was observed between maternal mid‐gestation SF and neonatal SF (p<0.05, n=52) and between placental FLVCR expression and the maternal delivery: neonatal SF ratio (p<0.01, n=43). Although FLVCR expression was regulated in response to maternal and neonatal Fe status, up‐regulation of this protein was not sufficient to normalize ferritin stores in neonates born to teens with depleted Fe stores. Funded by: NRI Grants 2008‐01857 & 2005‐35200, USDA HATCH (2006‐07‐160), and HHMI.