关键词: 低出生体重, 早产儿, Z评分, 追赶生长, 适于胎龄儿, 小于胎龄儿

Abstract: Objective To investigate the growth pattern and characteristics of low birth weight preterm infants within 2 years after birth, in order to promote proper physical growth in preterm infants. Methods Totally 123 low birth weight preterm infantsin the Department of Child Health Care, the Affliated Hospital of Qingdao University were enrolled in this study from January 2012 to December 2015, and were divided into small gestational age (SGA) infants and appropriate gestational age (AGA) infants.Longitudinal follow-up and intervention management of all children were performed.Weight, length and head circumference were regularly measured at 3,6,12 and 24 months after birth and WHO Anthro software was used to calculate the Z-scores of weight,length and head circumference.The growth indicators of premature infants with different characteristics were compared by repeated measures analysis of variance. Results 1) The overall weight, length and head circumference of premature infants showed an upward trend in Z score within 12 months after birth, but the increase was not obvious at the ages of 12 to 24 months.2) Comparison between SGA and AGA: the intra-group effect analysis indicated that the Z-scores of weight, length and head circumference of SGA and AGA groups generally showed an upward trend, with the fastest growth rate before the age of 6 months and slower growth after that.The Z-scores of the length of SGA group turned to a downward trend after the age of 12 months.The intergroup effect showed that Z-scores of the weight, length and head circumference at all age stages in the SGA group were significantly lower than the AGA group during the age of 3-24 months (F=5.653,5.644,7.163, P<0.05).The Z scores of weight, length and head circumference of the AGA group at 12 months and 24 months were close to the mean value of WHO standard children at the same age. Conclusions Preterm infants with low birth weight have catch-up growth in weight, length and head circumference within 24 months after birth.The catch-up growth mainly occurs within 12 months after birth, and the speed of the catch-up growth goes quickly at first, and then the increase speed slows down.Physical growth of AGA premature infants is better than that of SGA premature infants.

Key words: low birth weight, preterm infants, Z score, catch-up growth, appropriate gestational age infants, small gestational age