Growth until 24 months in preterm of very low birth weight, with or without intrauterine or postnatal growth restriction

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 (Fenton 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 according 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 restriction, 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 intrauterine and postnatal growth restriction) presents slow weight and length Z-score recovery, weight Zscore -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.