Oral or Poster Presentation
Concurrent Session 1D - Neonatal Clinical Trials
Introduction: Iron deficiency (ID) is the most common nutritional deficiency worldwide, and affects an estimated 39% of pregnant women globally. ID causes organ-specific patterns of hypoxia, mitochondrial dysfunction and oxidative stress in the fetus, however the effects on the offspring’s developing heart have not been studied. By virtue of iron’s role in ensuring oxygen delivery to the body, we sought to determine how the reduced oxygen carrying capacity associated with anemia during pregnancy and shortly after birth would affect cardiac morphology and function.
Methods: Sprague Dawley rats were fed an iron-restricted or iron-replete diet (control) prior to and throughout pregnancy. After birth, all dams were fed an iron-replete diet. On postnatal day (PD) 4, 14, and 28, hearts of male and female offspring were examined by echocardiography.
Results: Maternal iron restriction throughout pregnancy reduced maternal hemoglobin (-31%; P<0.001) and offspring hemoglobin from birth through PD14 (-48%, P<0.001; -25%, P=0.013). ID offspring exhibited growth restriction (-19%; P<0.001), which persisted through PD28 (-30%; P<0.001). When normalized to bodyweight, ID pups had increased heart weights at PD4 (+60%; P<0.001) and PD14 (+72%; P<0.001) and diastolic chamber volumes (+31%, P=0.005; +28%, P=0.056; respectively), and these values returned to control levels by PD28. After adjusting for body weight, ID offspring had reduced ejection fraction at PD4 (-15%; P=0.024) and PD14 (-19%; P=0.004), which normalized by PD28. These changes corresponded to a reduction in oxygen delivery on PD4 (-41%; P<0.001) and PD14 (-31%; P=0.05), which recovered completely by PD28.
Conclusion: Perinatal ID causes morphological and functional changes in the neonatal heart. With no corresponding increase in cardiac output, these results suggest a systolic dysfunction, which may reflect inadequate or maladaptive compensation in the wake of perinatal anemia. These findings may have important implications for the short and long-term cardiac health of anemic babies.