Direct and Indirect Effects of Breast Milk on the Neurobehavioral and Cognitive Development of Premature Infants Ruth Feldman Department of Psychology Bar-Ilan University Ramat-Gan, Israel, 52900 E-mail: feldman@mail.biu.ac.il Arthur I. Eidelman Department of Neonatology Shaare Zedek Medical Center Hebrew University School of Medicine Jerusalem, Israel ABSTRACT: Eighty-six premature infants were tested to examine the effects of maternal breast milk on infant development. Infants were classified by breast-milk consumption during the hospitalization period (M ¼ 57.4 days) into three groups: those receiving minimal (<25% of nutrition), intermediate (25–75%), and sub- stantial (>75%) amounts of breast milk. Infants in the three groups were matched for birth weight, gestational age (GA), medical risk, and family demographics. At 37 weeks GA, mother–infant interaction was videotaped, maternal depression self- reported, and neurobehavioral maturation assessed by the Neonatal Behavior As- sessment Seale (Brazelton, 1973). At 6 months corrected age, infants were tested with the Bayley II (Bayley, 1993). Infants receiving substantial amounts of breast milk showed better neurobehavioral profiles—in particular, motor maturity and range of state. These infants also were more alert during social interactions, and their mothers provided more affectionate touch. Higher maternal depression scores were associated with lower quantities of breast milk, longer latencies to the first breast-milk feeding, reduced maternal affectionate touch, and lower infant cogni- tive skills. Maternal affectionate touch moderated the relations between breast milk and cognitive development, with infants receiving a substantial amount of breast milk and frequent touch scoring the highest. In addition to its nutritional value, breast milk may be related to improved maternal mood and interactive behaviors, thereby indirectly contributing to development in premature infants. ß 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 109–119, 2003. Keywords: breast milk; premature infants; Neonatal Behavior Assessment Scale; neurodevelopment; cognitive development; Bayley; mother–infant interaction; maternal touch; maternal depression Whether breastfeeding exerts a lasting impact on children’s development has been an unresolved contro- versy for several decades (Jain, Concato, & Leventhal, 2002). Several large-scale studies demonstrated that children who were breast-fed as infants scored higher on IQ tests in childhood and adolescence (Johnson, Swank, Howie, Baldwin, & Owen, 1996; Mortensen, Michaelsen, Sanders, & Reinisch, 2002; Quinn et al., 2001). Critics, on the other hand, have argued that nursing mothers dif- fer from their nonnursing peers on a range of socio- demographic variables; they are older, more educated, and have a more supportive social network (Furman, Minich, & Hack, 1998; Lucas et al., 1998). Once socio- demographic factors were controlled, the effect of breast- feeding on intelligence was attenuated, suggesting that environmental conditions, not breast milk, per se, are the decisive factors in shaping infant development (Gale Received 25 June 2002; Accepted 15 March 2003 Correspondence to: R. Feldman, Department of Psychology, Bar-Ilan University, Ramat-Gan, Israel, 52900. Contract grant sponsor: Israeli Science Foundation Contract grant number: 945/01 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10126 ß 2003 Wiley Periodicals, Inc.