Department of Obstetrics and Gynecology, Diakonische Dienste Henriettenstiftung, Hannover, Germany.
Ultrasound Obstet Gynecol. 2010 Jan;35(1):42-7. doi: 10.1002/uog.7493.
To develop and test a specific formula for estimating weight in the macrosomic fetus.
Ultrasound estimations of fetal weight were carried out within 1 week of delivery in 424 singleton fetuses with a birth weight of > or = 4000 g. Exclusion criteria were multiple pregnancy, intrauterine death and major structural or chromosomal anomalies. Stepwise regression modeling was used to derive a prediction formula with birth weight as the dependent variable and maternal booking weight and fetal biometric measurements as independent parameters. After a new formula for estimated fetal weight (EFW) had been developed in a formula-finding group (n = 284), it was compared with commonly used weight equations (evaluation group, n = 140).
The new formula (log(e)EFW = 7.6377445039 + 0.0002951035 x maternal weight + 0.0003949464 x head circumference + 0.0005241529 x abdominal circumference + 0.0048698624 x femur length) proved to be superior to established equations, with the smallest mean error (mean +/- SD, -10 +/- 202 g), the smallest mean percentage error (mean +/- SD, -0.03 +/- 4.6%) and the lowest mean absolute percentage error (3.69 (range, 0.05-13.57)%) when studied in the evaluation group. With the new formula, 77.9% of estimates fell within +/- 5% of the actual weight at birth, 97.1% within +/- 10%, and 100% within +/- 15% and +/- 20%.
The new formula allows better weight estimation in the macrosomic fetus.
制定并检验一种适用于巨大儿体重预测的特定公式。
对 424 例出生体重≥4000g 的单胎巨大儿，于分娩前 1 周内行超声胎儿体重估测。排除标准为多胎妊娠、宫内死胎及严重结构或染色体异常。采用逐步回归建模，以出生体重为因变量，以孕妇初诊体重和胎儿生物测量参数为自变量，建立预测公式。在发现组（n=284）中开发出新的胎儿估计体重（EFW）公式后，与常用的体重公式（评估组，n=140）进行比较。
新公式（log(e)EFW=7.6377445039+0.0002951035x 孕妇体重+0.0003949464x 头围+0.0005241529x 腹围+0.0048698624x 股骨长）证明优于已建立的公式，在评估组中，其平均误差最小（均值±SD，-10±202g）、平均百分比误差最小（均值±SD，-0.03±4.6%）和平均绝对百分比误差最小（3.69（范围，0.05-13.57）%）。应用新公式，77.9%的估计值落在出生体重的±5%范围内，97.1%落在±10%范围内，100%落在±15%和±20%范围内。
新公式可更好地预测巨大儿体重。
