Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR, China.
Ultrasound Obstet Gynecol. 2018 Jun;51(6):792-798. doi: 10.1002/uog.17514.
To assess the suitability of the new INTERGROWTH-21 and World Health Organization (WHO) estimated fetal weight (EFW) references in a Southern Chinese population. A secondary aim was to determine the accuracy of EFW by assessing the difference between EFW and actual birth weight.
This was a prospective cross-sectional cohort study. Viable singleton pregnancies at 11-13 weeks' gestation were recruited to undergo a single standardized fetal biometric scan after 20 weeks. The gestational age at which the scan was performed was allocated randomly at the time of recruitment. EFW was predicted using both the Hadlock and INTERGROWTH-21 weight estimation model formulae. Population-specific EFW references were constructed. Z-scores were used to compare these references against the INTERGROWTH-21 and WHO international size references. Gestational-age-adjusted projection was used to assess the difference between EFW on the day of delivery and birth weight for fetuses having biometry scans ≥ 34 weeks.
Fetuses of 970 participants had biometry scans. The median number of scans per gestational week was 48 (interquartile range, 43-53). Z-score comparison indicated that the WHO 10 , 50 and 90 centiles of the EFW reference were consistently higher than the corresponding local centiles, whilst the INTERGROWTH-21 10 centile was lower. Fewer than 2% of fetuses scanned at or after 34 weeks would be considered as potentially large-for-gestational age, irrespective of which model was used to predict weight. Adopting the WHO international reference would result in approximately one in six fetuses being regarded as potentially small-for-gestational age, 50% more than the number determined using a population-specific reference. Systematic errors of extrapolated EFW were similar, ranging from 5.5% to 7.4%.
Centers seeking to use new references, such as the INTERGROWTH-21 and/or WHO international references, as a means of determining whether a fetus is small- or large-for-gestational age, would be advised to assess the suitability of these references within their own population using standardized methodology. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
评估新的 INTERGROWTH-21 和世界卫生组织（WHO）胎儿体重估计（EFW）参考值在中国南方人群中的适用性。次要目的是通过评估 EFW 与实际出生体重之间的差异来确定 EFW 的准确性。
这是一项前瞻性的横断面队列研究。在 11-13 孕周时招募了可行的单胎妊娠，并在 20 孕周后进行单次标准化胎儿生物测量扫描。扫描时的孕龄是在招募时随机分配的。使用 Hadlock 和 INTERGROWTH-21 体重估计模型公式预测 EFW。构建了特定人群的 EFW 参考值。使用 Z 分数将这些参考值与 INTERGROWTH-21 和 WHO 国际大小参考值进行比较。使用妊娠龄校正预测，评估生物测量扫描≥34 孕周的胎儿在分娩当天的 EFW 与出生体重之间的差异。
970 名参与者的胎儿进行了生物测量扫描。每孕周扫描中位数为 48 次（四分位距，43-53）。Z 分数比较表明，EFW 参考值的 WHO 第 10 、50 和 90 百分位数始终高于相应的本地百分位数，而 INTERGROWTH-21 的第 10 百分位数较低。使用任何一种模型预测体重，扫描时或扫描后≥34 孕周的胎儿中，只有不到 2%的胎儿被认为是潜在的胎龄过大，而采用 WHO 国际参考值，将导致大约六分之一的胎儿被认为是潜在的胎龄过小，比采用特定人群参考值的胎儿多 50%。外推的 EFW 系统误差相似，范围为 5.5%至 7.4%。
希望使用新的参考值（如 INTERGROWTH-21 和/或 WHO 国际参考值）来确定胎儿是小于胎龄儿还是大于胎龄儿的中心，建议使用标准化方法在其自身人群中评估这些参考值的适用性。版权所有 © 2017 ISUOG。由 John Wiley & Sons Ltd 出版。
