Prevalence and predictors of iron deficiency in fully breastfed infants at 6 mo of age: comparison of data from 6 studies.
BACKGROUND
Iron deficiency (ID) can occur among exclusively breastfed infants before 6 mo of age.


OBJECTIVE
The objective was to determine which subgroups of fully breastfed infants are at highest risk of ID.


METHODS
We assessed the prevalence of ID (ferritin < 12 mug/L) and iron deficiency anemia (IDA; ferritin < 12 mug/L and hemoglobin < 105 g/L) and risk factors associated with ID and IDA at 6 mo among 404 fully breastfed infants with a birth weight >2500 g from 6 studies in Ghana, Honduras, Mexico, and Sweden. Infants with an elevated C-reactive protein concentration (8%) were excluded.


RESULTS
The percentages of infants with ID were 6% in Sweden, 17% in Mexico, 13-25% in Honduras, and 12-37% in Ghana. The percentages with IDA were 2% in Sweden, 4% in Mexico, 5-11% in Honduras, and 8-16% in Ghana. With data pooled, the key predictors of ID (20%) were male sex [adjusted odds ratio (AOR): 4.6; 95% CI: 2.5, 8.5] and birth weight 2500-2999 g (AOR: 2.4; 95% CI: 1.4, 4.3). The predictors of IDA (8%) were male sex (AOR: 7.6; 95% CI: 2.5, 23.0), birth weight of 2500-2999 g (AOR: 3.4; 1.5, 7.5), and weight gain above the median since birth (AOR: 3.4; 95% CI: 1.3, 8.6). The combination of birth weight 2500-2999 g or male sex had a sensitivity of 91% for identifying ID and of 97% for identifying IDA.


CONCLUSIONS
Among fully breastfed infants with a birth weight >2500 g, IDA is uncommon before 6 mo, but male infants and those with a birth weight of 2500-2999 g are at higher risk of ID and IDA.
Yang
Zhenyu
Z
Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, USA.
Lönnerdal
Bo
B
Adu-Afarwuah
Seth
S
Brown
Kenneth H
KH
Chaparro
Camila M
CM
Cohen
Roberta J
RJ
Domellöf
Magnus
M
Hernell
Olle
O
Lartey
Anna
A
Dewey
Kathryn G
KG
D018798:Anemia, Iron-Deficiency / Q000453:epidemiology*; D001724:Birth Weight; D001942:Breast Feeding / Q000706:statistics & numerical data*; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D018579:Patient Selection; D011237:Predictive Value of Tests; D015995:Prevalence; D012727:Sex Characteristics; D015430:Weight Gain
D006454:Hemoglobins; D002097:C-Reactive Protein; D005293:Ferritins