[Growth until 24 months in preterm of very low birth weight, with or without intrauterine or postnatal growth restriction]. / Crecimiento a 24 meses de prematuros menores de 32 semanas, con o sin restricción de crecimiento intrauterino o postnatal.

INTRODUCTION: The growth of preterm newborns can be affected during the fetal period, hospitalization, and post discharge. OBJECTIVE: to describe the anthropometric development of preterm newborns with or without intrauterine and postnatal growth restriction, and with or without recovery at 40 weeks from birth to 24 months of age. PATIENTS AND METHOD: Retrospective, descriptive study with Z-scores (Fen ton and WHO) of weight, length, head circumference, and weight/length of preterm infants of less than 32 weeks of gestational age at birth up to 24 months of corrected age. 4 groups were defined ac cording to prenatal, postnatal, post-discharge growth as follows: Group AAA: newborns born AGA, with no postnatal growth restriction; Group APA: newborns born AGA, with postnatal growth res triction, weight < p10 at discharge, and weight > p10 at 40 weeks; Group APP: newborns born AGA, with postnatal growth restriction, weight < p10 at discharge and at 40w; and Group PPP: newborns born with intrauterine growth restriction and who maintained postnatal growth restriction (< p10 at birth, at discharge, and at 40w). We used descriptive statistics with ANOVA, Chi-squared, and linear mixed model analysis. RESULTS: 710 preterm newborns were included, birth weight 1272 grams (SD 360) and gestational age 29 weeks (SD 1.9). Group AAA had weight, length, and head circumference Z-scores close to the median until 2 years of age. AGA preterm newborns and with postnatal growth restriction can evolve in two ways: one group presents recovery at 40 weeks (Group APA) while the other group presents weight Z-score < -1 up to 6 months (Group APP). Group PPP (with intraute rine and postnatal growth restriction) presents slow weight and length Z-score recovery, weight Z- score -2.3 at discharge, and slow improvement to < -1 at 2 years of age. All groups had weight/height Z-scores above the median in the first 2 months of corrected age. CONCLUSION: Preterm newborns with good fetal growth but restricted postnatal growth, may recover at 40 weeks, with subsequent normal development or recover at 6 months.

[Risk factors for malnutrition at two years of corrected age in preterm infants under 32 weeks]. / Factores de riesgo de malnutrición a los dos años de edad corregida en prematuros menores de 32 semanas al nacer.

Post-discharge nutrition of preterm newborns must avoid excessive or insufficient weight gain and optimal length and head circumference growth. In Chile, premature infants less than 32 wee ks at birth receive fortified formulas during the first year, unless they are exclusively breastfed. OBJECTIVE: To describe growth and identify the risk of malnutrition at 24 months. PATIENTS AND METHOD: Retrospective cohort study that analyzes growth from birth to 2 years of corrected age in preterm patients < 32 weeks of gestational age. Z-score of weight, length, head circumference, and Body Mass Index (BMI) were analyzed. Factors related to Z BMI at 24 months were analyzed as follows: Eutrophic: Z BMI between -1 and +1; Overweight: Z BMI > +1; Underweight: Z BMI < -1. RESULTS: 996 preterm infants were included, 559 completed check-ups at 24 months. 64.5% were eutrophic, 18.4% overweight, and 17.1% underweight. Multivariate analysis showed that risk of overweight was associated with birth weight > 1460 g: OR 5.77 (2.11-15.77) and Z BMI > 1.6 at 6 months: OR 2.67 (1.91-3.74); underweight risk was associated with birth weight < 1000g: OR 3.1 (1.1-8.8) and Z BMI < -0.75 at 6 months: OR 8.2 (4.3-16.3). CONCLUSIONS: The greater risk of overweight and underweight can be anticipated in premature infants under 32 weeks with birth weight or Z BMI at 6 months of corrected age.