RESUMO
BACKGROUND: Placental supply of fatty acids (FA) is essential for normal foetal development but in premature infants this supply is interrupted. To investigate the association of intrautrine growth restriction with serum phospholipid and breast milk FA composition, we compared preterm infants small for gestational age (SGA) and matched appropriate for gestational age (AGA), and their mothers' milk during the first 4 weeks of postnatal life. METHODS: Sera from 11 SGA and 12 AGA infants born 34-36 weeks of gestation were collected at birth, 14(th) and 28(th) day, and breast milk on 14(th) and 28(th) day after birth. FA composition was analyzed by gas chromatography. RESULTS: Preterm SGA infants had significantly lower oleic, total monounsaturated FA (MUFA), docosahexaenoic acid (DHA) and n-3 polyunsaturated FA (PUFA) and higher levels of stearic and linoleic acid at birth than AGA infants (p<0.05). DHA was significantly lower, whereas docosatetraenoic and docosapentaenoic acids were higher in SGA infants after 28 days. Mothers of AGA infants had markedly lower levels of MUFA and higher levels of total and n-6 PUFA in their breast milk. CONCLUSION: SGA infants have altered serum phospholipid FA composition at birth and during their first month of life, probably due to inadequate transplacental supply and activity of desaturase system. RESULTS on human milk suggest that pregnancies with AGA or SGA would later influence breast milk FA composition.