Factors influencing the growth of preterm infants in the first two years of life.

OBJECTIVE

To identify maternal and neonatal factors associated with growth outcomes in preterm infants (PT) born before 33 weeks of gestation, assessed at 24 months corrected age (CA).

METHODS

Prospective cohort study with PT <33 weeks' gestation, discharged from the Neonatal Intensive Care Unit of a university hospital between 2019 and 2021, followed at the high-risk outpatient clinic. Variables analyzed: Maternal - sociodemographic aspects, gestational morbidities, selfefficacy score (confidence that parents have in their ability to perform the tasks of parenthood); Newborn - data from birth, hospital stay and post-discharge, measures of weight, height and head circumference at birth, discharge and follow up (seven evaluations). Outcome: Z scores of anthropometric measurements and growth failure (Z score <-2) at 24 months CA. Data were analyzed by hierarchical logistic or linear regression models in blocks.

RESULTS

99 PT with a mean gestational age of 30.2±2.0 weeks were studied. Intrauterine growth restriction (fetus that fails to reach its growth percentage, caused by maternal/placental factors) and being born small for gestational age (<10th percentile according to Fenton's calculator) were predictors of growth failure. Time to achieve full enteral feeding, necrotizing enterocolitis and maternal self-efficacy were associated with anthropometric measurements at 24 months.

CONCLUSIONS

The growth of PT in the first 24 months CA is influenced by the nutritional condition at birth, nutritional evolution during hospitalization and maternal self-efficacy. Optimizing nutritional practices for PT and stimulating maternal self-efficacy are possibilities for improving growth in the early years.