巨大胎儿体质量估测新公式的建立和验证

New weight estimation formula for macrosomic fetuses

目的 创建用于巨大胎儿体质量估测新公式,并将新公式和现有的25个公式进行比较.方法 对1153例胎儿（其中239例巨大胎儿）在出生前1周以内行产科超声检查,测量胎儿双顶径（BPD）、头围（HC）、腹围（HC）、和股骨长（FL）,出生后记录胎儿体质量.采用逐步回归法设计新公式,1034例（914例非巨大胎儿＋120例巨大胎儿）数据用于建立新的全范围体质量预测公式,239例巨大胎儿中120例数据为训练集,被用于建立疑似巨大胎儿胎重估测公式,其余119例巨大胎儿（测试集）用于公式验证,并与国内外常用25个公式相比较.结果 全范围体质量估测公式为：lgBW=0.180（HC）＋0.00628 （AC）-0.00318（HC）2＋0.00173 （AC） （FL）＋0.0000430 （BPD） （HC）2.疑似巨大胎儿胎重估测公式为：lgBW=0.730（BPD） -0.0375 （BPD）2＋0.000264 （AC） （FL）.新估测公式对119例测试集的平均误差为（- 87.89±230.95）g,平均绝对百分误差为（4.4±3.9）％,25个公式中误差最小公式的平均估测误差为（115.61±345.09）g,平均绝对百分误差为（6.8±5.4）％,新公式与公认的其他常用公式相比,平均绝对误差、平均绝对百分误差均为最低.结论 新公式评估胎儿体质量的准确性较高.新公式适宜于评估中国胎儿体质量,尤其适合评估巨大胎儿体质量.

Objective To develop a new formula to estimate macrosomia weight and compared with published 25 formulas.Methods 1153 fetuses including 239 macrosomia within one week of delivery were considered.Two-dimensional ultrasound measurements of the fetal biparietal diameter （BPD）,head circumference （HC）,abdominal circumference （AC） and femur length （FL） were performed and recorded by experienced sonographers.The birth weight were measured after the babies born.The formula finding group,1034 fetuses including 914 fetuses weighting less than 4000g and 120 macrosomia,were utilized to generate an overall regression formula by stepwise linear regression.120 macrosomia were used to established the formula for estimating macrosomic weight.As the training group,other 119 macrosomia were used to test the new formula and compared with other 25 existing formulas.Results The new formula for whole weight was：lgBW =0.180 （HC） ＋ 0.00628 （AC） - 0.00318 （HC）2 ＋ 0.00173 （AC） （FL） ＋0.0000430（BPD）（HC）2.The new formula for macromia was：lgBW =0.730（BPD） -0.0375 （BPD）2 ＋0.000264（AC） （FL）.The new method gave （ - 87.89 ± 230.95）g of estimation error and （4.4 ± 3.9） % of absolute percentage error,while the best existing formula provided （115.61± 345.09）g and （6.8 ± 5.4）%.With the new method,89.1% of estimates fell within ± 10% of the actual birth weight,while the best existing formula gave 75.6%.Conclusions The new formula was based on typical Chinese Han women,the error was lower and more suitable than those developed formulas for Chinese populations,especially for macrosomia fetuses.