PLACENTAL PROTEINS INVOLVED IN IRON HOMEOSTASIS WERE DOWNREGULATED IN GESTATIONAL DIABETES MELLITUS

Background: High iron status in pregnancy has been associated with increased risk of gestational diabetes mellitus (GDM). Hyperglycaemia in GDM has been suggested to affect processes involved in placental iron homeostasis, but it is unclear whether these affect transfer of iron to the fetus.

 

Objectives: To compare maternal and fetal iron status, and placental proteins involved in iron homeostasis, in women with and without GDM

 

Methods: Primigravidae, with and without GDM, were followed up through pregnancy until delivery. Hematological and iron-related parameters were estimated in maternal and cord blood samples. Placental tissue obtained was used to estimate tissue iron content and to determine gene expression of proteins involved in iron homeostasis.

 

Results: Women with GDM (n = 30) and those without (n = 77) had similar sociodemographic and clinical characteristics; hematological and iron-related parameters in maternal blood were similar in the 2 groups. In cord blood from mothers with GDM, reticulocyte count and serum ferritin values were lower than in those without (p values = 0.027 and 0.055 respectively). Gene expression of placental ferroportin, ferritin-H and ZIP8 were significantly lower in those with GDM than in those without. Other relevant genes and iron content in the placentae were similar in both groups.

 

Conclusions: Placental expression levels of proteins involved in iron homeostasis were lower

in women with GDM than in those without, implying less transfer of iron to the fetus in these women. Findings of lower levels of serum ferritin and reticulocyte counts in the cord blood corroborate this observation.