Growth Patterns of Preterm Infants: A Comparative Study by Gestational Age † 1320

Abstract

Hypothesis: Infants born at younger GA demonstrate poor physical growth compared to those of higher GA. Obj: Comparison of growth of preterm AGA infants by gest. age and examine factors that could potentially affect growth. Setting: Level 3 NICU & Neurodevelopmental follow-up clinic. Sample: 134 preterm infants, 104 of whom had follow-up evaluations. Methods: Measurements of wt, length and head circumference at birth, discharge and 4, 8 and 12 months' corrected age (CA) were obtained for 3 groups of AGA infants(23-25 wks', 26-28 wks' and 29-31 wks' GA). Factors thought to affect growth(lung disease, sepsis, PDA, age at introduction & duration of TPN and age of 1st feeding) were also recorded. Results: Infants in all 3 GA groups fell from similar percentiles at birth to significantly lower percentiles at discharge with the younger GA infants doing much worse than the higher GA group. However, all 3 groups experienced significant catch-up growth by 4 months' CA, especially the younger GA infants despite significant comorbidity. In contrast to female infants who continued to grow well, Male infants < 26 wks' GA at birth dropped off significantly in weight & head circumference from 4 to 12 months' CA but were similar in length to higher GA groups. Conclusions: Irrespective of GA at birth, preterm AGA infants born between 23 & 31 wks' GA have potential for significant catch-up growth. This persists despite significant morbidity in the younger GA infants. Speculation: Possible contributors to catch-up growth include optimal in-hospital nutrition preserving potiential for later growth, improvement in chronic lung disease, positive impact of home environment including ad libitum feeds & consistent care provider. Table