Akolekar R, Syngelaki A, Gallo D M, Poon L C, Nicolaides K H
Department of Fetal Medicine, Medway Maritime Hospital, Gillingham, Kent, UK.
Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
Ultrasound Obstet Gynecol. 2015 Jul;46(1):82-92. doi: 10.1002/uog.14842. Epub 2015 Jun 1.
To investigate the potential value of cerebroplacental ratio (CPR) at 36 weeks' gestation in the prediction of adverse perinatal outcome.
This was a screening study in 6178 singleton pregnancies at 35-37 weeks' gestation. Umbilical artery (UA) and fetal middle cerebral artery (MCA) pulsatility index (PI) were measured and the values were converted to multiples of the median (MoM) after adjustment from variables in maternal characteristics and medical history that affect the measurements. CPR was calculated by dividing MCA-PI MoM by UA-PI MoM. Multivariable logistic regression analysis was used to determine if measuring CPR improved the prediction of adverse perinatal outcome provided by maternal characteristics, medical history and obstetric factors. The detection rate (DR) and false-positive rate (FPR) of screening by CPR were estimated for stillbirth, Cesarean section for fetal distress, umbilical arterial cord blood pH ≤ 7.0, umbilical venous cord blood pH ≤ 7.1, 5-min Apgar score < 7 and admission to the neonatal unit (NNU) and neonatal intensive care unit (NICU).
There was a linear association between CPR and both birth-weight Z-score and arterial or venous umbilical cord blood pH, but the steepness of the regression lines was inversely related to the interval from assessment to delivery. The performance of low CPR < 5(th) percentile in screening for each adverse outcome was poor, with DRs of 6-15% and a FPR of about 6%. In the small subgroup of the population delivering within 2 weeks of assessment, the DRs improved to 14-50%, but with a simultaneous increase in FPR, to about 10%.
The performance of CPR in routine screening for adverse perinatal outcome at 36 weeks' gestation is poor.
探讨孕36周时脑胎盘比率（CPR）在预测围产期不良结局中的潜在价值。
这是一项对6178例孕35 - 37周单胎妊娠的筛查研究。测量脐动脉（UA）和胎儿大脑中动脉（MCA）搏动指数（PI），并根据影响测量的母体特征和病史变量进行调整后，将这些值转换为中位数倍数（MoM）。CPR通过将MCA - PI MoM除以UA - PI MoM来计算。采用多变量逻辑回归分析来确定测量CPR是否能改善由母体特征、病史和产科因素提供的围产期不良结局预测。估计CPR筛查死产、因胎儿窘迫行剖宫产、脐动脉血pH≤7.0、脐静脉血pH≤7.1、5分钟阿氏评分<7以及入住新生儿病房（NNU）和新生儿重症监护病房（NICU）的检出率（DR）和假阳性率（FPR）。
CPR与出生体重Z评分以及脐动脉或脐静脉血pH之间存在线性关联，但回归线的斜率与评估至分娩的间隔呈负相关。低CPR<第5百分位数对每种不良结局的筛查效果较差，DR为6 - 15%，FPR约为6%。在评估后2周内分娩的小部分人群中，DR提高到14 - 50%，但同时FPR增加到约10%。
孕36周时CPR在常规筛查围产期不良结局中的表现较差。
