Nowacka U, Papastefanou I, Bouariu A, Syngelaki A, Akolekar R, Nicolaides K H
Fetal Medicine Research Institute, King's College Hospital, London, UK.
Fetal Medicine Unit, Medway Maritime Hospital, Gillingham, UK.
Ultrasound Obstet Gynecol. 2022 Feb;59(2):177-184. doi: 10.1002/uog.23730. Epub 2022 Jan 12.
First, to investigate the additive value of second-trimester placental growth factor (PlGF) for the prediction of a small-for-gestational-age (SGA) neonate. Second, to examine second-trimester contingent screening strategies.
This was a prospective observational study in women with singleton pregnancy undergoing routine ultrasound examination at 19-24 weeks' gestation. We used the competing-risks model for prediction of SGA. The parameters for the prior model and the likelihoods for estimated fetal weight (EFW) and uterine artery pulsatility index (UtA-PI) were those presented in previous studies. A folded-plane regression model was fitted in the dataset of this study to describe the likelihood of PlGF. We compared the prediction of screening by maternal risk factors against the prediction provided by a combination of maternal risk factors, EFW, UtA-PI and PlGF. We also examined the additive value of PlGF in a policy that uses maternal risk factors, EFW and UtA-PI.
The study population included 40 241 singleton pregnancies. Overall, the prediction of SGA improved with increasing degree of prematurity, with increasing severity of smallness and in the presence of coexisting pre-eclampsia. The combination of maternal risk factors, EFW, UtA-PI and PlGF improved significantly the prediction provided by maternal risk factors alone for all the examined cut-offs of birth weight and gestational age at delivery. Screening by a combination of maternal risk factors and serum PlGF improved the prediction of SGA when compared to screening by maternal risk factors alone. However, the incremental improvement in prediction was decreased when PlGF was added to screening by a combination of maternal risk factors, EFW and UtA-PI. If first-line screening for a SGA neonate with birth weight < 10 percentile delivered at < 37 weeks' gestation was by maternal risk factors and EFW, the same detection rate of 90%, at an overall false-positive rate (FPR) of 50%, as that achieved by screening with maternal risk factors, EFW, UtA-PI and PlGF in the whole population can be achieved by reserving measurements of UtA-PI and PlGF for only 80% of the population. Similarly, in screening for a SGA neonate with birth weight < 10 percentile delivered at < 30 weeks, the same detection rate of 90%, at an overall FPR of 14%, as that achieved by screening with maternal risk factors, EFW, UtA-PI and PlGF in the whole population can be achieved by reserving measurements of UtA-PI and PlGF for only 70% of the population. The additive value of PlGF in reducing the FPR to about 10% with a simultaneous detection rate of 90% for a SGA neonate with birth weight < 3 percentile born < 30 weeks, is gained by measuring PlGF in only 50% of the population when first-line screening is by maternal factors, EFW and UtA-PI.
The combination of maternal risk factors, EFW, UtA-PI and PlGF provides effective second-trimester prediction of SGA. Serum PlGF is useful for predicting a SGA neonate with birth weight < 3 percentile born < 30 weeks after an inclusive assessment by maternal risk factors and biophysical markers. Similar detection rates and FPRs can be achieved by application of contingent screening strategies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
第一，研究孕中期胎盘生长因子（PlGF）对预测小于胎龄儿（SGA）新生儿的附加价值。第二，研究孕中期的条件性筛查策略。
这是一项对单胎妊娠妇女进行的前瞻性观察性研究，这些妇女在妊娠19 - 24周时接受常规超声检查。我们使用竞争风险模型来预测SGA。先前模型的参数以及估计胎儿体重（EFW）和子宫动脉搏动指数（UtA-PI）的似然值均来自先前的研究。在本研究的数据集中拟合了一个折面回归模型来描述PlGF的似然性。我们将母体风险因素筛查的预测结果与母体风险因素、EFW、UtA-PI和PlGF联合提供的预测结果进行了比较。我们还研究了PlGF在使用母体风险因素、EFW和UtA-PI的策略中的附加价值。
研究人群包括40241例单胎妊娠。总体而言，随着早产程度增加、胎儿生长受限严重程度增加以及子痫前期并存，SGA的预测准确性提高。对于所有检查的出生体重和分娩孕周临界值，母体风险因素、EFW、UtA-PI和PlGF的联合显著改善了仅由母体风险因素提供的预测。与仅通过母体风险因素进行筛查相比，通过母体风险因素和血清PlGF联合进行筛查可改善SGA的预测。然而，当将PlGF添加到由母体风险因素、EFW和UtA-PI联合进行的筛查中时，预测的增量改善有所降低。如果对出生体重低于第10百分位数且在妊娠<37周分娩的SGA新生儿进行一线筛查采用母体风险因素和EFW，那么通过仅对80%的人群进行UtA-PI和PlGF测量，可实现与在整个人群中使用母体风险因素、EFW、UtA-PI和PlGF进行筛查相同的90%的检测率，总体假阳性率（FPR）为50%。同样，在筛查出生体重低于第10百分位数且在<30周分娩的SGA新生儿时，通过仅对70%的人群进行UtA-PI和PlGF测量，可实现与在整个人群中使用母体风险因素、EFW、UtA-PI和PlGF进行筛查相同的90%的检测率，总体FPR为14%。当一线筛查采用母体因素、EFW和UtA-PI时，通过仅对50%的人群测量PlGF，可将FPR降低至约10%，同时对出生体重低于第3百分位数且在<30周出生德SGA新生儿的检测率达到90%，从而获得PlGF的附加价值。
母体风险因素、EFW、UtA-PI和PlGF的联合可在孕中期有效预测SGA。在通过母体风险因素和生物物理标志物进行全面评估后，血清PlGF有助于预测出生体重低于第3百分位数且在<30周出生的SGA新生儿。应用条件性筛查策略可实现相似的检测率和FPR。©2021国际妇产科超声学会。
