低出生体重儿婴儿期体格生长指标参考值偏度系数-中位数-变异系数法研究

目的  了解合肥市主城区低出生体重儿（low birth weight infant，LBWI）0~12月体格生长状况，掌握合肥市早产低出生体重儿和足月小样儿婴儿期生长轨迹。 方法  建立出生队列，228名LBWI进入队列，选取同期同机构接受健康管理的161名正常出生体重儿（normal birth weight infant，NBWI）作为对照组，监测婴儿0~12月龄体格生长指标，以偏度系数-中位数-变异系数（lambda-mu-sigma，LMS）法计算性别年龄别体重、身长各百分位数值，并绘制LMS曲线。 结果  婴儿期LBWI组体重、身长等指标均明显低于NBWI组，差异有统计学意义（均有P < 0.001）；LBWI 3月龄体重达到出生时2.5倍，12月龄体重约为出生时4.3倍，12月龄身长为出生时1.6倍；总体上LBWI组在生后第1年尤其在6月龄前体重、身长呈追赶生长趋势，早产低出生体重儿追赶生长速度快于足月小样儿。 结论  LBWI在婴儿期存在追赶生长，LMS法建立的合肥市早产低出生体重儿与足月小样儿婴儿期生长曲线客观地描述了两者不同的体格生长特点和轨迹。

Lambda-mu-sigma method(LMS) study on the physical growth reference standard of low birth weight infant

  Objective  To investigate the physical growth status of low birth-weight infants (LBWI) from 0 to 12 months in main urban area of Hefei City, so as to obtain the growth trajectory of premature low birth-weight infants and mature low birth-weight infants in Hefei.  Methods  A birth cohort was established, totally 228 LBWI entered the cohort, 161 normal birth weight infant (NBWI) from the same center were selected as control group. The physical growth indicators were monitored during 0-12 months, the percentile values of weight and length for age and gender were calculate by using lambda-mu-sigma(LMS) method, and LMS curves were drew.  Results  The body weight and length of LBWI group were significantly lower than those of NBWI group during the infancy stage, and the difference was statistically significant (all P < 0.001). The weight of LBWI was 2.5 times heavier at 3 months than at birth, 4.3 times heavier at 12 months than at birth, and the length of LBWI was 1.6 times longer at 12 months than at birth.In general, the LBWI group showed a catch-up growth trend on weight and length in the first year, especially under 6 months. The catch-up growth rate of premature low-birth-weight infants was faster than that of mature low birth-weight infants.  Conclusions  There is catch-up growth of LBWI during 0-12 months. The growth curves by LMS method of premature low birth weight infants and mature low birth-weight infants can objectively describe their different physical growth characteristics and trajectories.