DOES FULL BREASTFEEDING FOR SIX MONTHS PLACE U.S. INFANTS AT RISK FOR ANEMIA? Caroline J Chantry ¹, Cynthia R Howard ² and Peggy Auinger³. ¹Pediatrics, University of California Davis Medical Center, Sacramento, CA; ²Pediatrics, University of Rochester, Rochester, NY; and ³Center for Child Health Research, American Academy of Pediatrics, Rochester, NY.

BACKGROUND: The AAP recommends exclusive breastfeeding for 6 months (mos). Exclusive breastfeeding to 6 mos, however, can lead to iron (Fe) deficiency in susceptible infants. Few data have evaluated the effect of these recommendations on Fe status of US children.

OBJECTIVE: To ascertain if full breastfeeding for 6 mos places US children at greater risk for Fe deficiency than full breastfeeding of lesser duration.

DESIGN/METHODS:: Data regarding 2,268 children ages 6 to <24 mos from NHANES III, a nationally representative cross-sectional survey conducted from 1988-94, were analyzed. Anemia [either low hemoglobin (hgb) or history (hx) of anemia] and Fe status (serum ferritin) were compared for 5 groups: formula fed only (n=1142), or full breastfeeding for: <1 mo "FullBF<1" (n=425), 1 mo to <4 mos "FullBF1-3+" (n=343), 4 to <6 mos "FullBF4-5+" (n=222),and 6 mos "FullBF6+" (n=136). Lab data were available for 745 children aged 12 to <24 mos. Median durations of full breastfeeding in the 4 breastfed groups were 5, 61, 122 and 182 days. Children requiring NICU care were excluded. SUDAAN software was used to account for the complex sampling design. Logistic regression controlled for confounding factors.

RESULTS: In unadjusted analyses, 9.9% of "FullBF6+" had a hx of anemia compared to 2.3% of "FullBF4-5+", (p=.007). At time of survey, lab differences were not significant: 1.7 % vs. 0.2% w/ low hgb and 9.9% vs. 10.6% w/ low ferritin. Adjusting for age, birthweight, ethnicity, poverty, 2 parent household, and parental education revealed persistent increased risk for anemia hx in "FullBF6+" compared to "FullBF4-5+" (p=.007, OR 5.1, CI 1.6,16.2) and "FullBF1-3+" (p=.039, OR 3.2, CI 1.1,9.5). Still no difference was found in risk of low hgb between "FullBF6+" vs. "FullBF4-5+" and the "FullBF<1"and "FullBF1-3+" groups were actually at higher risk of low hgb values. Adjusted risk of low ferritin did not differ between groups. Recent use of Fe containing supplements did not affect the adjusted risks of low hgb or ferritin, or hx of anemia.

CONCLUSIONS: Young children in the US who are fully breastfed for 6 mos may be at increased risk of anemia. Adequate Fe may not be provided by typical complementary infant foods. Health care providers should be vigilant to prevent Fe deficiency in this group of infants.