A Survey On Physical Growth Of Late Preterm Infants Aged1Year In Chongqing City

Objective To investigate the physical growth of late preterm infants（LPI） and to provide the basis for growth evaluation of LPI. MethodsInfants were recruited for a cohort study in Department of Primary ChildHealth Care, Children’s Hospital, Chongqing Medical University from May2010to November2011. LPI and full term infants （FTI） were comparedin terms of weight for age Z-scores（WAZ）, length for age Z-scores（LAZ）,head circumference for age Z-scores（HCZ）,weight for length Z-scores（WLZ）and the velocity of all physical growth indicator （ΔWAZ,ΔLAZ,ΔHCZ）.Compared with neonatal physical growth investigation results of15cities ofChina in1986, to evaluate the birth weight （BW） in different gestationalages. Results（1）309LPI and418FTI were included. Compared with FTI,BW of LPI（2518.05±463.80）g was significantly lower than that of the FTI（3225.91±404.91）（gp<0.01）.Compared with the neonatalphysicalgrowthinvestigation results of15cities of China in1986, the average BW ingestational ages of34and35weeks were less than corresponding gestationalages,but36weeks’ mean BW of LPI was higher than the reference value（;2） Before6～months,WAZ and HCZ of LPI were lower than FTI and in8～months at the level of FTI.LAZ of LPI did not reach the FTI’s level within1year old;（3）At1month corrected age,all physical indicators of LPI wereover the level of FTI and the differences had statistically significant;（4）TheLPI gained obviously more in weight,length and head circumference thanFTI within1year of age（p<0.0001）. ΔWAZ_1-4, ΔLAZ_1-4, ΔLAZ_4-8andΔHCZ_1-4were1.74±0.89,1.24±0.79,0.79±0.7and0.98±0.83respectively;（5）On corrected ages, the incidence of wasting in LPI had significantstatistically differences in FTI at5～and6～months and overweight in LPIwas significantly higher than in FTI at8～months（P=0.0475）, while theincidences of stunting were similar. Conclusion （1） There is an obviouschanges on LPI’s BW,comparing with the neonatal physical growthinvestigation results of15cities of China in1986.Therefore we shouldupdate the reference of BW at different gestational ages in a certain interval;（2） It needs further research what should be the time to discontinue to usecorrected gestational age for assessing growth indicators of LPI;（3） LPIgrow faster than FTI, and there is a “catch-up growth” in LPI.（4） LPI havehigher risk of growth deviation than FTI.