不同出生体重晚期早产儿婴儿期体格生长的纵向研究

Evaluation of physical growth of late preterm infants with different birth weight during infancy:a longitudinal study

目的探讨正常出生体重(NBW)和低出生体重(LBW)晚期早产儿(LPI)婴儿期的体格生长特点,为临床更好地评价和管理早产儿提供依据。方法选择2010年至2020年在重庆医科大学附属儿童医院儿童保健科就诊,并在实际年龄为3、6、12月龄定期随访的140例LPI,按照出生体重分为LBW组(<2500g)和≥NBW组(2500g),比较两组早产儿实际年龄的生长水平、生长速度及生长偏离情况。结果(1)在纳入的140例LPI中,LBW组占49.29%(69/140),NBW组占50.71%(71/140)。两组的出生体重差异有统计学意义(t=-14.581,P<0.001),而胎龄、性别、喂养方式差异均无统计学意义(P>0.05)。(2)生长水平:在3、6、12月龄时,LBW组体重、身长、头围的Z值中位数均小于NBW组(W=1129.51392.0,P<0.05);12月龄时的生长指标[年龄别体重Z值(WAZ)、年龄别身长Z值(HAZ)、年龄别头围Z值(HcAZ)]≥-2的比例,LBW组为91.30%、71.01%、95.65%,NBW组为100.00%、97.18%、100.00%。(3)生长速度:在3、6、12月龄时,两组体重、身长、头围的生长速度差异均无统计学意义(P>0.05)。(4)生长偏离:12月龄时,LBW组生长障碍发生率高于NBW组(χ^(2)=19.440,P<0.001);LBW组超重/肥胖发生率低于NBW组(χ^(2)=9.254,P=0.002)。结论出生体重的差异不影响LPI婴儿期体重、身长和头围的生长速度;婴儿期NBW早产儿体格生长状况优于LBW早产儿,NBW早产儿体格生长指标在第1年结束时几乎全部达到足月儿童参照标准,且超重发生率高,而LBW早产儿生长障碍发生率高于NBW早产儿。有必要进一步对LPI生长速度的影响因素及体格评价的矫正年龄开展多中心研究。

Objective To investigate the physical growth of late preterm infants(LPI) with normal birth weight(NBW) and low birth weight(LBW) during infancy,so as to provide evidences for better clinical evaluation and management of preterm infants.Methods A total of 140 LPIs treated in Children′s Hospital Affiliated to Chongqing Medical University from 2010 to 2020 and followed up regularly at the age of 3,6 and 12 months were recruited,and divided into LBW group(<2 500 g) and NBW group(≥2 500 g) according to their birth weight.The growth level,growth rate and growth deviation of actual age for LPIs in the two groups were compared.Results(1)Among the 140 LPIs,49.29%(69/140) were LBW infants and 50.71%(71/140) were NBW infants.The differences of birth weight between two groups were significant(t=-14.581,P<0.001),but differences of gestational age,gender,and feeding methods between the two groups were not significant(P>0.05).(2)At the age of 3,6 and 12 months,the median of weight-for-age Z-score(WAZ),height-for-age Z-score(HAZ) and head circumference-for-age Z-score(HcAZ) in the LBW group were significantly lower than those in the NBW group(W=1129.5~1392.0,all P<0.05).At 12 months of age,the proportions of WAZ,HAZ and HcAZ≥-2 in the LBW group and NBW group were(91.30%、71.01%、95.65%) and(100.00%、97.18%、100.00%),respectively.(3)There were no significant differences in the growth rates of weight,length and head circumference at the age of 3,6,and 12 months between the two groups(all P>0.05).(4)At 12 months of age,the LBW group had a significantly higher rate of growth disorders than the NBW group(χ2=19.440,P<0.001),and the incidence of overweight/obesity in the NBW group was significantly higher than the LBW group(χ2=9.254,P=0.002).Conclusion The difference of birth weight does not affect the growth rates of weight,length and head circumference of late preterm infants during infancy.The physical growth levels of LPI with normal birth weight in infancy are better than that of infants with low birth weight.At the end of the first year,LPI with NBW almost completely reached the reference standard for full-term infants,and the rate of overweight is higher than LPI with LBW.The rate of growth disorders in LPI with LBW is higher than that of LPI with NBW.It is necessary to conduct a multi-center study on the influencing factors of the growth rate of late preterm infants and the corrected age of physical evaluation.