ArticlesBackground: Our aim was to determine the influence of breastfeeding and postnatal nutrition on cardiovascular remodeling induced by fetal growth restriction (FGR). Methods: A cohort study including 81 children with birthweight <10th centile (FGR) and 121 with adequate fetal growth for gestational age (AGA) was conducted. Cardiovascular endpoints were left ventricular sphericity index (LVSI), carotid intima-media thickness (cIMT), and blood pressure (BP) at 4-5 y of age. The combined effect of FGR and postnatal variablesincluding breastfeeding, fat dietary intake, and BMI-on cardiovascular endpoints was assessed by linear and robust regressions. results: FGR was the strongest predictor of cardiovascular remodeling in childhood, leading to lower LVSI and increased cIMT and BP as compared with AGA. Breastfeeding >6 mo (coefficient: 0.0982) and healthy-fat dietary intake (coefficient: −0.0128) showed an independent beneficial effect on LVSI and cIMT, respectively. Overweight/obesity induced an additional increment of 1 SD on cIMT in FGR children (interaction coefficient: 0.0307) when compared with its effect in AGA. BMI increased systolic BP (coefficient: 0.7830) while weight catchup increased diastolic BP (coefficient: 4.8929). conclusions: Postnatal nutrition ameliorates cardiovascular remodeling induced by FGR. Breastfeeding and healthy-fat dietary intake improved while increased BMI worsened cardiovascular endpoints, which opens opportunities for targeted postnatal interventions from early life. t here is consistent epidemiological evidence that low birth weight is inversely associated with cardiovascular mortality in adulthood (1,2). The most common cause of low birth weight is fetal growth restriction (FGR) due to placental insufficiency (3). FGR fetuses present cardiovascular remodeling already in utero that persist into childhood (4,5). This effect is thought to contribute to their subsequent long-term cardiovascular risk (6). One of the most prominent signs of cardiac remodeling associated with FGR in fetal life and childhood is a more spherical heart measured by lower values on left ventricular sphericity index (LVSI) (5). Likewise, children who suffered FGR have signs of vascular dysfunction, including increased blood pressure (BP) (7) and carotid intima-media thickness (cIMT) (5) which are well-known cardiovascular risk factors.Nutrition and body weight have a strong effect on cardiovascular development during childhood (8). Therefore, the effects of intrauterine environment on cardiovascular remodeling should be influenced by postnatal factors. Epidemiological studies suggest that obesity in childhood or accelerated postnatal growth could worsen the cardiovascular risk associated with impaired intrauterine growth. Moreover, high dietary intake of polyunsaturated fatty acids (PUFA) has been associated with lower cIMT values in children with FGR (9). However, the deleterious or protective effects of nutrition and body weight on cardiovascular remodeling have not been evaluated longitudinally in a ...