中国不同出生胎龄新生儿体重身长比、体质指数和重量指数的参照标准及生长曲线

目的:制定中国出生胎龄24~42周新生儿体重身长比、体质指数和重量指数的参照标准及生长曲线,为新生儿出生时身体比例及营养状况评价提供参考依据。方法:横断面研究,于2015年6月至2018年11月在北京、哈尔滨、西安、上海、南京、武汉、广州、福州、昆明等13个城市调查出生胎龄24~42周单胎活产新生儿24375名,排除了影响参照标准建立的母亲和新生儿因素。采用基于位置、尺度、形状的广义可加模型构建出生胎龄24~42周男、女新生儿体重身长比、体质指数和重量指数的百分位数(P 3、P 10、P 25、P 50、P 75、P 90、P 97)参照值及生长曲线。将研制的参照标准与我国1988年数值、INTERGROWTH项目及美国相关参照值进行比较。结果:24375名新生儿中早产儿12264名(男7042名、女5222名),足月儿12111名(男6155名、女5956名)。研制出出生胎龄24~42周男、女新生儿体重身长比、体质指数和重量指数百分位数生长参照值及生长曲线。男新生儿体重身长比在不同出生胎龄P 10、P 50、P 90上比女新生儿高0~0.2 kg/m,男新生儿体质指数在不同出生胎龄P 10、P 50、P 90上比女新生儿高0.1~0.3 kg/m²。体重身长比和体质指数曲线在高百分位数上、重量指数曲线在高、低百分位数上与我国1988年数值均有较大差异,如体重身长比、体质指数、重量指数与我国1988年数值在P 90上的差值范围分别为-1.09~0.40 kg/m、-1.19~0.92 kg/m²、-0.64~0.81 kg/m³。体重身长比曲线与INTERGROWTH项目参照值有较好的一致性,在P 50上的差值范围-0.17~0.20 kg/m,出生胎龄≤32周时在P 90上低0.02~0.40 kg/m、在P 10上高0.13~0.41 kg/m。体质指数曲线与美国参照值差异较为明显,在P 50上的差值范围-0.47~0.17 kg/m²,出生胎龄≥37周时在P 90上低0.53~1.10 kg/m²但≤28周时高0.17~0.45 kg/m²。结论:建立中国出生胎龄24~42周新生儿不同性别的体重身长比、体质指数和重量指数的标准化参照值,可供临床及相关科研工作参照使用。

Reference values and growth curves of weight/length,body mass index,and ponderal index of Chinese newborns of different gestational ages

Objective To establish the reference values and growth curves of weight/length,body mass index,and ponderal index for Chinese newborns with gestational ages of 24 to 42 weeks,in order to provide a reference for the assessment of body proportionality and nutritional status at birth.Methods Cross-sectional study design was applied.From June 2015 to November 2018,a total of 24375 singleton live birth newborns with gestational ages of 24 to 42 weeks from 13 cities including Beijing,Harbin,Xi′an,Shanghai,Nanjing,Wuhan,Guangzhou,Fuzhou,Kunming,Tianjin,Shenyang,Changsha,and Shenzhen were selected,excluding those impacting the establishment of the reference values.The generalized additive model for location,scale,and shape(GAMLSS)was employed to establish percentile(P3,P10,P25,P50,P75,P90,P97)reference values and growth curves of weight/length,body mass index,and ponderal index for male and female newborns with gestational ages of 24 to 42 weeks.The established growth standards in this study were compared with the standards from the 1988 Chinese data,the INTERGROWTH project,and the USA reference values.Results A total of 24375 newborns with 12264 preterm newborns(7042 males and 5222 females)and 12111 full-term newborns(6155 males and 5956 females)were included in this study.The percentile reference values and growth curves of weight/length,body mass index,and ponderal index were obtained for male and female newborns with gestational ages of 24 to 42 weeks.Weight/length of males in all gestational ages at P10,P50 and P90 was 0 to 0.2 kg/m higher than that of females,and body mass index of males in all gestational ages at the P10,P50 and P90 was 0.1 to 0.3 kg/m² higher than that of females.The established growth curves of weight/length and body mass index at the upper percentile and ponderal index at both upper and lower percentiles were greatly different from those of the 1988 Chinese data,which,for example,reported the difference ranges at P90 as-1.09 to 0.40 kg/m for weight/length,-1.19 to 0.92 kg/m2 for body mass index,and-0.64 to 0.81 kg/m³ for ponderal index.The established weight/length curves were generally consistent with the reference values from the INTERGROWTH project with a difference of-0.17 to 0.20 kg/m at P50,while being 0.02 to 0.40 kg/m lower at P90 and 0.13 to 0.41 kg/m higher at P10 than that of the INTERGROWTH reference values at gestational ages of≤32 weeks.The established body mass index curves differed from that of the USA reference values with a difference of-0.47 to 0.17 kg/m2 at P50,while being 0.53 to 1.10 kg/m^(2 )lower at gestational ages of≥37 weeks but 0.17 to 0.45 kg/m2 higher at gestational ages of≤28 weeks than that of the USA reference values at P90.Conclusion The establishment of the new standardized growth reference values of weight/length,body mass index,and ponderal index for Chinese newborns by different gestational ages are useful for clinical practice and scientific research.