Early infant feeding and growth status of US-born infants and children aged 4-71 mo: analyses from the third National Health and Nutrition Examination Survey, 1988-1994.

BACKGROUND: There is controversy over what growth references to use in evaluating breast-fed infants and concern about whether never-breast-fed infants are at risk of overweight in childhood. OBJECTIVE: The objective of this study was to determine whether infants who are exclusively breast-fed for 4 mo differ in average size from infants who are fed in other ways and whether such differences persist through age 5 y. DESIGN: Data from the third National Health and Nutrition Examination Survey (NHANES III) were linked to birth certificates of US-born infants and children. Feeding groups were defined on the basis of feeding patterns over the first 4 mo of life: exclusively breast-fed for 4 mo, partially breast-fed, breast-fed for <4 mo, and never breast-fed. Growth status, indexed as internally derived z scores (SD units) for weight, length (height), weight-for-length (height), midupper arm circumference, and triceps skinfold thickness, was compared among feeding groups. RESULTS: The final sample consisted of 5594 non-Hispanic white, non-Hispanic black, and Mexican American infants and children aged 4-71 mo. Of these, 21% were exclusively breast-fed for 4 mo, 10% were partially breast-fed, 24% were breast-fed for <4 mo, and 45% were never breast-fed. At 8-11 mo, infants who were exclusively breast-fed for4 mo had adjusted mean z scores for weight (-0.21; -0.2 kg), weight-for-length (-0.27), and midupper arm circumference (-0.15) that differed significantly from zero (P < 0. 05). By 12-23 mo, the differences had dissipated; there were no significant differences subsequent to 5 y. Triceps skinfold thickness was not related to early infant feeding. CONCLUSION: Infants who were exclusively breast-fed for 4 mo weighed less at 8-11 mo than did infants who were fed in other ways, but there were few other significant differences in growth status through age 5 y associated with early infant feeding.