Prenatal Iron Status and Its Association With Cord Blood and Infant Ferritin Level
Prenatal Iron Status and Its Association With Cord Blood and Infant Ferritin Level
Iron deficiency (ID) in early life is associated with significant morbidities. Most fetal
 iron required for infant growth is acquired in the third trimester from maternal iron store.
 However, how prenatal iron level affects newborn's ferritin level at birth and in early
 infancy remains controversial. This study aimed to examine the associations between maternal
 ferritin levels with cord blood serum ferritin (CBSF) and to compare the ferritin levels
 between different feeding practices in early infancy.
Iron deficiency (ID) is the most common micronutrient deficiency globally. Pregnant women and
 young children are at risk of ID. During pregnancy, there is an increased demand for iron to
 accommodate the needs of the fetal-placental unit. This increase in physiologic demand for
 iron renders pregnant women vulnerable to ID. In fact, ID is the major cause of anemia in
 pregnancy and can increase the perinatal maternal morbidity and mortality. Iron is also an
 essential micronutrient for fetal and infant brain development. ID in early life is
 associated with worse cognitive, motor, social emotional as well as neurophysiological
 development. Besides neurodevelopment, iron is also essential for proper immune function
 affecting both innate and adaptive cell, and has implications for childhood atopic diseases.

 Globally, there is an increasing trend of breastfeeding especially in developed countries.In
 Hong Kong, the government's continuing effort to promote breastfeeding has successfully
 boosted the rate of babies being breastfed. This encouraging information means more children
 will benefit from the many advantages of breast milk over formula milk, yet exclusive
 breastfeeding, particularly in the context of maternal ID and late weaning, may be a risk
 factor of ID in the infants. In view of the adverse impact of fetal and infant ID on
 neurocognitive development, it is important to evaluate the iron status of young infants, the
 effect of feeding practices on development of ID and the risk factors of ID in early infancy.

 Maternal ID is prevalent worldwide varying from 20% to 90%. Previous investigation performed
 in the Department of Obstetrics and Gynaecology, Prince of Wales Hospital, concurred a
 significant prevalence (39%) of ID (serum ferritin < 15 microgram/L) among 100 asymptomatic
 pregnant women. Most fetal iron needed for infant growth is acquired in the third trimester
 from maternal iron store, in preparation for the high growth rate in the first 6 months of
 life. Iron status at birth is therefore critical and impaired iron status may persist into
 early childhood. However, low maternal prenatal iron levels measured as serum ferritin have
 not been consistently linked with low cord blood serum ferritin (CBSF) concentrations. Some
 studies reported that there was no correlation between serum ferritin of mothers and babies.
 However, others found that maternal ID or anemia, especially the severe type, adversely
 affected cord blood or infant iron status. Further studies are needed to evaluate how
 prenatal maternal iron status affects newborn's ferritin level at birth. Such data is
 necessary to guide future recommendations regarding the need of iron supplement in pregnant
 or lactating women and/or their infants. Hence, this study aimed to examine the associations
 between maternal prenatal ferritin levels with CBSF and to compare the ferritin levels with
 different feeding practices in early infancy at 3 months of age.
Inclusion Criteria:

 -  Women who carried a singleton pregnancy without any history of thyroid dysfunction,
 hyperemesis gravidarum, autoimmune disease, or any other major medical condition with
 cord blood available were eligible for this study

 Exclusion Criteria:

 -  multiple pregnancy, preterm delivery at less than 37 weeks of gestation, infants with
 congenital anomalies, syndromal diseases, chronic renal or hepatic diseases, metabolic
 disease, chronic gastrointestinal diseases and/or malabsorption