Maternal Serum Ferritin Concentration Is Positively Associated with Newborn Iron Stores in Women with Low Ferritin Status in Late Pregnancy

Abstract

Iron deficiency (ID) is common in pregnant women and infants, particularly in developing countries. The relation between maternal and neonatal iron status remains unclear. This study considered the issue in a large sample of mother-newborn pairs in rural southeastern China. Hemoglobin (Hb) and serum ferritin (SF) were measured in 3702 pregnant women at ≥37 wk gestation and in cord blood of their infants born at term (37-42 wk gestation). Maternal anemia (Hb <110 g/L) was present in 27.5% and associated with maternal SF <20 μg/L in 86.9%. Only 5.6% of neonates were anemic (Hb <130 g/L) and 9.5% had cord-blood SF <75 μg/L. There were low-order correlations between maternal and newborn iron measures (r = 0.07-0.10 for both Hb and SF; P ≤ 0.0001 due to the large number). We excluded 430 neonates with suggestion of inflammation [cord SF >370 μg/L, n = 208 and/or C-reactive protein (CRP) >5 mg/L, n = 233]. Piecewise linear regression analyses identified a threshold for maternal SF at which cord-blood SF was affected. For maternal SF below the threshold of 13.6 μg/L (β = 2.4; P = 0.001), cord SF was 0.17 SD lower than in neonates whose mothers had SF above the threshold (167 ± 75 vs. 179 ± 80 μg/L). The study confirmed that ID anemia remains common during pregnancy in rural southeastern China. Despite widespread maternal ID, however, iron nutrition seemed to meet fetal needs except when mothers were very iron deficient. The impact of somewhat lower cord SF on iron status later in infancy warrants further study.

The placenta: the forgotten essential organ of iron transport

“…A recent study in China, which included a large sample of mother-child pairs (n ¼ 3702), detected a strong correlation between maternal and neonatal ferritin in women whose plasma ferritin levels fell below a threshold of depletion, with every unit of decrease in maternal serum ferritin corresponding to a 2.4-unit drop in cord ferritin. 118 This finding is consistent with rodent data indicating a "broken stick" relationship between maternal and fetal iron parameters, suggesting a critical point below which the two become dependent. 102 While most mechanistic studies are modeled on healthy pregnancy, it is worth noting that conditions with underlying placental abnormalities, such as intrauterine growth restriction and gestational diabetes, may disrupt the normal regulatory mechanism of the placenta and negatively affect fetal iron transfer.…”

Selected trace elements concentrations in pregnancy and their possible role — literature review

“…According to Wang et al, the impact of iron supplementation in pregnancy on the birth weight of the child depends on the concentration of hemoglobin in maternal blood before pregnancy [9]. A significant decrease in fetal iron was observed in pregnant women with anemia [10].…”

“…During pregnancy, the body's iron requirement significantly increases, especially in the third trimester [9,10]. Preg- nant women are therefore advised to use iron and folic acid supplements to reduce the risk of developing anemia [8].…”

The Relationship between Iron Deficiency and Thyroid Function in Chinese Women during Early Pregnancy

“…Numerous and compelling scientific evidence has shown that IDA during pregnancy is linked with a wide variety of adverse maternal and perinatal outcomes, such as preterm birth, low birth weight and unhealthy neurodevelopment in the fetus (16). And it is now clear that neonatal iron stores can be compromised when the mother is iron deficient or anemic (17).…”