Fetal Medicine Research Institute, King's College Hospital, London, UK.
Fetal Medicine Unit, Medway Maritime Hospital, Gillingham, UK.
Ultrasound Obstet Gynecol. 2019 Apr;53(4):488-495. doi: 10.1002/uog.20243.
To evaluate the performance of ultrasonographic estimated fetal weight (EFW) at 35 + 0 to 36 + 6 weeks' gestation in the prediction of delivery of a small-for-gestational-age (SGA) neonate and assess the additive value of, first, maternal risk factors and, second, fetal growth velocity between 20 and 36 weeks' gestation in improving such prediction.
This was a prospective study of 44 043 singleton pregnancies undergoing routine ultrasound examination at 19 + 0 to 23 + 6 and at 35 + 0 to 36 + 6 weeks' gestation. Multivariable logistic regression analysis was used to determine whether addition of maternal risk factors and growth velocity, the latter defined as the difference in EFW Z-score or fetal abdominal circumference (AC) Z-score between the third- and second-trimester scans divided by the time interval between the scans, improved the performance of EFW Z-score at 35 + 0 to 36 + 6 weeks in the prediction of delivery of a SGA neonate with birth weight < 10 and < 3 percentiles within 2 weeks and at any stage after assessment.
Screening by EFW Z-score at 35 + 0 to 36 + 6 weeks' gestation predicted 63.4% (95% CI, 62.0-64.7%) of neonates with birth weight < 10 percentile and 74.2% (95% CI, 72.2-76.1%) of neonates with birth weight < 3 percentile born at any stage after assessment, at a screen-positive rate of 10%. The respective values for SGA neonates born within 2 weeks after assessment were 76.8% (95% CI, 74.4-79.0%) and 81.3% (95% CI, 78.2-84.0%). For a desired 90% detection rate of SGA neonate delivered at any stage after assessment, the necessary screen-positive rate would be 33.7% for SGA < 10 percentile and 24.4% for SGA < 3 percentile. Multivariable logistic regression analysis demonstrated that, in the prediction of a SGA neonate with birth weight < 10 and < 3 percentiles, there was a significant contribution from EFW Z-score at 35 + 0 to 36 + 6 weeks' gestation, maternal risk factors and AC growth velocity, but not EFW growth velocity. However, the area under the receiver-operating characteristics curve for prediction of delivery of a SGA neonate by screening with maternal risk factors and EFW Z-score was not improved by addition of AC growth velocity.
Screening for SGA neonates by EFW at 35 + 0 to 36 + 6 weeks' gestation and use of the 10 percentile as the cut-off predicts 63% of affected neonates. Prediction of 90% of SGA neonates necessitates classification of about 35% of the population as being screen positive. The predictive performance of EFW is not improved by addition of estimated growth velocity between the second and third trimesters of pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
评估 35 周+0 至 36 周+6 周妊娠时超声估计胎儿体重（EFW）在预测小于胎龄儿（SGA）新生儿中的表现，并评估母亲危险因素以及妊娠 20 周至 36 周之间胎儿生长速度的附加价值，以改善这种预测。
这是一项对 44043 例单胎妊娠的前瞻性研究，这些妊娠在 19 周+0 至 23 周+6 周和 35 周+0 至 36 周+6 周进行常规超声检查。多变量逻辑回归分析用于确定是否添加母亲危险因素和生长速度（后者定义为第三和第二 trimester 扫描之间的 EFW Z-score 或胎儿腹围（AC）Z-score 差异除以扫描之间的时间间隔）可以改善 35 周+0 至 36 周+6 周妊娠时 EFW Z-score 在预测出生体重 <10 和 <3 百分位的 SGA 新生儿在 2 周内和评估后任何阶段分娩中的表现。
35 周+0 至 36 周+6 周妊娠时的 EFW Z-score 筛查预测出生体重 <10 百分位的新生儿的 63.4%（95%CI，62.0-64.7%）和出生体重 <3 百分位的新生儿的 74.2%（95%CI，72.2-76.1%），筛查阳性率为 10%。评估后任何阶段出生的 SGA 新生儿在 2 周内的相应值分别为 76.8%（95%CI，74.4-79.0%）和 81.3%（95%CI，78.2-84.0%）。为了达到在评估后任何阶段出生的 SGA 新生儿 90%的检出率，SGA <10 百分位的必要筛查阳性率为 33.7%，SGA <3 百分位的为 24.4%。多变量逻辑回归分析表明，在预测出生体重 <10 和 <3 百分位的 SGA 新生儿中，EFW Z-score 在 35 周+0 至 36 周+6 周妊娠、母亲危险因素和 AC 生长速度有显著贡献，但 EFW 生长速度没有贡献。然而，使用母亲危险因素和 EFW Z-score 进行筛查预测 SGA 新生儿分娩的受试者工作特征曲线下面积并未因添加 AC 生长速度而得到改善。
35 周+0 至 36 周+6 周妊娠时通过 EFW 筛查 SGA 新生儿，并将 10 百分位作为截止值，可以预测 63%的受影响新生儿。预测 90%的 SGA 新生儿需要将约 35%的人群分类为筛查阳性。EFW 的预测性能不能通过添加妊娠 2 至 3 trimester 之间的估计生长速度来改善。
