The burden of extra uterine growth restriction on postnatal growth in very low birth weight preterm newborns

Background: Extra-uterine growth restriction (EUGR) is a condition caused by the failure of very preterm infants to reach their potential growth during the NICU hospital stay. Despite improvements in nutritional supports, their growth pattern is still far from that expected. EUGR is now recognized as a major risk factor for long-term metabolic, anthropometric, and cognitive outcomes. Aim of our study was to evaluate anthropometric and metabolic outcome at peripubertal age in a population of ex-preterm VLBW infants and to detect the possible influence of EUGR on short stature. Methods: Retrospective cohort study of children born in a single centre between 2005 and 2009 with VLBW (birth weight < 1500 g). Families were recruited by telephone. During the clinical evaluation at peri-pubertal age, we measured height, head circumference, weight, and Body Mass Index (BMI), and clinical laboratory tests. Data were analyzed using SPSSv10.0 (SPSS Inc., Chicago, IL, USA). The Mann-Whitney U test was used for inter-group comparisons of continuous variables, and the Spearman test was used for correlations between variables. For intra-group comparisons, the paired t-test was used. Differences among three or more groups were assessed using the non-parametric Kruskal–Wallis test. Results: We enrolled 78 patients, 21 (27%) born Small for Gestational Age (SGA). Comparing anthropometrics at discharge with those at birth, a significant impairment was found in the whole population for weight, length, and head circumference SDS (p < 0.001). EUGR was detected in all the children born SGA and in 50% of the children born AGA. At peripubertal age four subjects presented with short stature (5.19%): all were EUGR, and three were on rhGH treatment. Patients who developed asymmetric EUGR had lower HDL cholesterol (p:0.049) and higher fasting blood glucose value at peripubertal age, compared to our population (p:0.049). Conclusion: Our data confirm SGA infants at birth develop EUGR at discharge and are associated with metabolic development noted at the peripubertal age. Recording anthropometric parameters during the NICU hospital stay is crucial, as they are related to weight, BMI, and metabolic risk factors at peripubertal age. Trial registration: Local Ethics Committee approved the protocol (AVEN CE N. 124/2018).