| dc.description.abstract | Backgrounds: Iron is an essential micronutrient that must be obtained from the diet. Pregnant women and infants are vulnerable groups of iron deficiency, due to elevated requirement at these life stages characterized by rapid growth and development. Sufficient iron status is critical for the development of the fetus and in early stages in life, having a central role in the development of the brain and nervous system. Despite the important role of iron, there is a lack of recent data on iron status in pregnant women and infants in Norway.
Objective: The primary aim of this thesis was to describe maternal and infant iron status, in a population group based in Norway. The secondary aim was to explore how factors such as dietary intake, supplement use, and breastfeeding were associated with maternal and infant iron status.
Methods: The Mommy`s Food study was used as a secondary analysis where iron status was assessed in a longitudinal cohort study of pregnant and postpartum women and their infants in Bergen. Serum ferritin (s-ferritin) was used as a biomarker for iron status and was measured in the participants at gestational week (GW) 18 (n=137), GW 36 (n=119), 3 months (n=112), and 6 months postpartum (n=106), and in their infants at 3 months (n=47) and 6 months of age (n=50). S-ferritin levels <15 µg/L was used as the cut-off defining iron deficiency for the women, whereas s-ferritin <12 µg/L was used as the cut-off indicating iron deficiency in infants. At the same timepoints, comprehensive dietary information was collected through a food frequency questionnaire (FFQ).
Results: During pregnancy, at GW 18, the median s-ferritin levels were 33 µg/L and 14% of the women were iron deficient. At GW 36, the median s-ferritin decreased to 8 µg/L and 68% of the women were classified as iron deficient. At 3 months postpartum, the median s-ferritin were 22 µg/L and 22% were iron deficient, while at 6 months postpartum the median was 25 µg/L and 14% were iron deficient. In the infants, at 3 months of age, the median s-ferritin were 168 µg/L and 0% were classified as iron deficient. By 6 months of age, the median s-ferritin decreased to 48 µg/L and 6% were iron deficient. Maternal use of iron supplements was associated with significantly higher maternal s-ferritin levels at GW 36 and 3 months postpartum. Maternal consumption of red meat showed no impact on maternal s-ferritin status. No significant difference was observed in infant s-ferritin status between infants only breastfed compared to those breastfed and formula-fed, and the only formula-fed infants. There was no observed difference in infant s-ferritin status between the infants that got primarily industrially made porridge compared to homemade porridge.
Conclusion: A low iron status was observed among the pregnant and postpartum women. Particularly, a high prevalence of iron deficiency was found towards the end of pregnancy where almost all women had s-ferritin levels indicating depleted iron stores. In contrast, the infants iron status was adequate at both 3 and 6 months of age, suggesting that the infants’ iron needs are prioritized before the mothers in pregnancy. Considering the effect of dietary factors affecting iron status, the findings revealed a limited impact. Iron supplementation had an effect on maternal iron status at two timepoints, beyond this, no impact of maternal red meat intake, or infant breastfeeding status and porridge consumption was observed on iron status in this study. | |
