317 - Extrauterine growth restriction trajectory by Intergrowth-21 vs Fenton growth charts

Poster Number: 317
Publication Number: 317.129

Lena Olgun, Icahn School of Medicine at Mount Sinai - - New York, NY, White Plains, NY, United States; Andrea Weintraub, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Robert S.. Green, Icahn School of Medicine at Mount Sinai, New York, NY, United States

Background: Fostering optimal neurodevelopmental outcomes of preterm infants with extrauterine growth restriction (EUGR) while avoiding potential consequences of aggressive nutritional approaches is of utmost importance. However, there is currently no consensus for which growth assessment tool should be used to monitor postnatal growth of preterm infants.

Objective: The aim of our study was to compare the prevalence and progression of EUGR on the Fenton and Intergrowth-21 growth standards from inpatient to outpatient follow up, and to examine which factors were associated with EUGR to better identify patients at risk.

Design/Methods: In this single center retrospective study, we reviewed weight, length and head circumferences at birth, at 36 weeks corrected gestational age (CGA), and at the 1st and 2nd outpatient follow-up visits for preterm infants born between 24 and 32 weeks gestational age (GA) who were followed after hospital discharge in our NICU Neurodevelopmental Follow-Up Clinic. We compared the prevalence and progression of EUGR, defined as a decrease in weight z-score < -1, from birth to 36 weeks CGA, using the Fenton and Intergrowth-21 growth standards and evaluated the longitudinal progression of growth from inpatient to outpatient follow-up. We evaluated factors associated with EUGR using a logistic regression model.

Results: Of the 647 infants seen in our follow up clinic since 2017, 369 were born between 24 and 32 weeks gestation. Mean GA at birth was 29.3 weeks, and age at 1st and 2nd outpatient visits were 56.5 and 86.5 weeks, respectively. The prevalence of EUGR was 16% when using Intergrowth-21, and 61% when using Fenton growth standards. Although there was a significant decrease in z-score for weight from birth to 36 weeks CGA (p < 0.001), there was no difference in the weight z-score from birth to the 2nd clinic visit (p = 0.994). EUGR was associated with lower GA at birth, a higher z-score for weight at birth, necrotizing enterocolitis (NEC), and need for CPAP at 36 weeks CGA.

Conclusion(s): The proportion of infants identified as EUGR at 36 weeks CGA differed with use of Intergrowth charts when compared with Fenton growth charts and was less prevalent when using Intergrowth-21. Growth failure during the NICU stay is common in preterm infants and associated with lower GA, higher birth weight z-score, NEC, and CPAP at 36 weeks CGA. Catch up growth occurred as an outpatient with return to their birth weight z-score.