Background: The X syndrome, related to coronary disease in adults, could be possibly programmed priory to delivery, in children with intrauterine growth retardation. Aim: To measure serum lipids in newborns with symmetrical or asymmetrical intrauterine growth retardation. Patients and methods: One hundred thirty five newborns with intrauterine growth retardation and 116 normal term newborns, with 38 to 41 gestational weeks, were studied. Total, HDL, and LDL cholesterol, triglycerides and apoproteins. A1 and B were measured in imbilical cord blood samples. Results: No differences in total, HDL, LDL cholesterol, apoproteins A1 and B were observed between the study groups. Triglycerides were higher in newborns with intrauterine growth retardation, compared to normal term newborns (45 ± 27 and 36 ± 19 mg/dl respectively, p<0,001). Differences in serum triglyceride levels respect to controls were observed in both male and female newborns with asymmetrical growth retardation. Likewise the differences respect to controls were observed in newborns with mild or severe but not with moderate growth retardation. Conclusions: Newborns with intrauterine growth retardation have higher triglyceride levels than normal term newborns. (Rev Méd Chile 2000; 128: 741-8).