Effect of heredity on hemoglobin concentration

The influences of factors associated with decreased iron supply to the fetus during pregnancy on iron status in healthy children aged 0.5 to 3 years

OBJECTIVE

To investigate whether maternal anemia, pregnancy-induced diabetes, hypertension and smoking contributed to the recently found high prevalence of iron deficiency in a population of otherwise healthy children.

STUDY DESIGN

Iron status was assessed in 400 children aged 0.5 to 3 years. We obtained information on the mothers' laboratory results, the presence of diabetes and hypertension, smoking habits and use of medication while pregnant.

RESULT

We found no influence of maternal anemia, diabetes, hypertension or smoking during pregnancy on iron status in the children. Mean corpuscular volume (MCV) values of the children were positively correlated to maternal MCV values.

CONCLUSION

In this population, iron status in children is not affected by maternal anemia or maternal factors that are associated with a decreased iron transport during pregnancy. The correlation between MCV values in mothers and their children might be explained by genetic and/or shared environmental factors.

Predictors of iron status in well-nourished 4-y-old children

BACKGROUND

Iron status in childhood is influenced by diet. Other factors affecting iron status at that age are unclear.

OBJECTIVES

The objectives of the study were to evaluate iron status in 4-y-old children, to track that status from infancy to childhood, and to examine the associations of iron status with dietary factors, growth, and heredity.

DESIGN

This study consisted of a longitudinal follow-up at age 4 y of children (n = 127) from the cohort of a study that began at age 6 mo. Blood samples and anthropometry were assessed in both children and their parents; food records were collected from children only.

RESULTS

Dietary intake was not significantly correlated with hemoglobin concentrations, whereas the consumption of meat products had a positive effect on serum ferritin concentrations and mean corpuscular volume in boys (P = 0.015 and 0.04, respectively). The prevalences of anemia and iron deficiency were low, affecting 2 (1.8%) and 3 (2.8%) children, respectively; no child had iron deficiency anemia. There was significant within-subject tracking of hemoglobin and mean corpuscular volume from age 6 mo to 4 y. The mother's but not the father's hemoglobin correlated with the child's hemoglobin over time.

CONCLUSIONS

Food choices had little effect on iron status. Hemoglobin concentrations and mean corpuscular volume were tracked from infancy to childhood. In healthy, well-nourished children with a low prevalence of iron deficiency, the mother's hemoglobin was significantly associated with that of her child, but the underlying mechanism is unclear.