Longitudinal Study of Catch-up Growth Assessed by Anthropometric Parameters in Very Premature Infants within 3 Years Old

Abstract

BackgroundThe improvement in perinatal medicine has promoted the increase of survival rate in very premature infants. Since growth and developmental delays will have a long-term impact on them, early catch-up growth is extremely important. However, there are few longitudinal studies on anthropometric parameters for assessing catch-up growth in such infants.ObjectiveTo investigate the increasing trend of body weight, body length and head circumference (HC) of very premature infants within 3 years old, providing evidence for promoting scientific catch-up growth in such infants.MethodsParticipants were selected from Northern Jiangsu People's Hospital during August 2017 to September 2018, including 120 ICU-treated very premature infants delivered at 28-32 weeks of gestation, who were divided into two group 〔small for gestational age (SGA) group (n=11) and appropriate for gestational age (AGA) group (n=109) 〕, and 121 full-term infants. Body weight and length as well as HC were measured at 40 weeks, 3, 6, 12, 24 months of corrected age and 36 months, respectively, and Z-scores and growth rates of these three parameters were calculated.ResultsThe Z-scores of body weight, body length and HC differed statistically across SGA, AGA and full-term infants within 12 months of corrected age (P<0.05) . The catch-up growth for weight peaked within 3 months of corrected age in AGA infants and full-term infants, and it peaked within 3 to 6 months of corrected age in SGA infants. The growth for height showed a significant increase trend within 6 months of corrected age in AGA and full-term infants. For SGA infants, the catch-up growth for height peaked within 3 to 6 months of corrected age. The HC of AGA infants had an obvious trend of catch-up growth within 3 months of corrected age, while SGA infants'catch-up growth for HC was obvious after 3 months of corrected age, and it gradually slowed down after 12 months of corrected age. The body weight growth rate varied statistically across SGA, AGA and full-term infants during 40 weeks to 12 months of corrected age (P<0.05) . There were statistically differences of growth rates in body length and HC between the three groups during 40 weeks to 24 months of corrected age (P<0.05) .ConclusionThe trends of catch-up growth for body weight, height and HC were significantly different between SGA and AGA infants within 3 years old. Compared with AGA infants, the early catch-up growth rates of these three parameters in SGA infants were slower and imbalanced. Compared to full-term infants, the early catch-up growth rates of the three parameters in very premature infants were significantly slower. And the time point of peak for catch-up growth for each parameter varied significantly between SGA and AGA infants.

Keywords

• |infant, extremely premature|small for gestational age|appropriate for gestational age|z scores|catch-up growth