Mater Research Institute, The University of Queensland, South Brisbane, Queensland, Australia.
School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
Ultrasound Obstet Gynecol. 2017 Oct;50(4):514-519. doi: 10.1002/uog.17371. Epub 2017 Sep 5.
To evaluate whether the magnitude of change in the cerebroplacental ratio (CPR) after 30 weeks' gestation is a better predictor of adverse pregnancy outcome compared with a single CPR measurement at 35-37 weeks. A secondary aim was to evaluate whether the utility of CPR at 35-37 weeks was enhanced after adjusting for change in gestational age.
This was a retrospective cohort study of women who had at least two ultrasound scans between 30 and 37 weeks' gestation, with the final scan at 35-37 weeks. Exclusion criteria were major congenital abnormality, aneuploidy, multiple pregnancy and unknown middle cerebral artery pulsatility index or umbilical artery pulsatility index. A normal reference range for CPR was derived from a separate cohort of women with normal outcome and a Generalised Additive Model for Location, Scale and Shape was fitted to derive standardized centiles. These reference centiles were then used to calculate Z-scores for the study cohort. Logistic regression models and receiver-operating characteristics (ROC) curves were used to evaluate the predictive utility of CPR Z-score at last CPR measurement and the change in CPR on mode of delivery, neonatal outcome and composite neonatal outcome. The area under the ROC curve (AUC) for each model was compared before and after adjustment for parity, hypertension, diabetes, body mass index and smoking status.
A total of 1860 women met the inclusion criteria. There was no association between the magnitude of change in CPR and composite adverse pregnancy outcome (P = 0.92). Of the outcomes that made up the composite, an increase in CPR Z-score over time was associated with a lower risk for emergency Cesarean delivery (P < 0.001) and emergency Cesarean delivery for non-reassuring fetal status (P = 0.02). It was also associated with a lower risk of birth weight < 10 centile (P = 0.01) and hypoglycemia (P = 0.001). There was no significant difference between the AUCs of last CPR Z-score and last CPR Z-score adjusted for the change in gestational age in predicting pregnancies at risk for adverse outcome.
Our results suggest that both the individual CPR Z-score and the magnitude and direction of change in CPR Z-score can identify pregnancies at risk of various adverse perinatal outcomes. However, the CPR Z-score at 35-37 weeks' gestation appears to be a better predictor. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
评估与 35-37 孕周的单次脑-胎盘比（CPR）测量相比，妊娠 30 周后 CPR 变化幅度是否能更好地预测不良妊娠结局。次要目的是评估在调整胎龄变化后，35-37 孕周时的 CPR 是否更有用。
这是一项回顾性队列研究，纳入至少在妊娠 30-37 周之间进行了两次超声检查、且最后一次检查在 35-37 周的孕妇。排除标准为主要先天性异常、非整倍体、多胎妊娠和未知大脑中动脉搏动指数或脐动脉搏动指数。从正常结局的另一组孕妇中得出 CPR 的正常参考范围，并拟合广义加性模型进行位置、比例和形状的标准化分位数。然后使用这些参考百分位数为研究队列计算 Z 分数。使用逻辑回归模型和受试者工作特征（ROC）曲线来评估最后一次测量时的 CPR Z 分数和 CPR 变化对分娩方式、新生儿结局和复合新生儿结局的预测价值。在调整了产次、高血压、糖尿病、体重指数和吸烟状况后，比较了每个模型的 ROC 曲线下面积（AUC）。
共纳入 1860 名符合条件的孕妇。CPR 变化幅度与复合不良妊娠结局之间没有关联（P=0.92）。在构成复合结局的各结局中，CPR Z 分数随时间增加与急诊剖宫产（P<0.001）和非安慰性胎儿状态的急诊剖宫产（P=0.02）风险降低相关。CPR Z 分数增加还与出生体重<第 10 百分位数（P=0.01）和低血糖（P=0.001）风险降低相关。在预测有不良结局风险的妊娠时，最后一次 CPR Z 分数与调整胎龄变化后的最后一次 CPR Z 分数的 AUC 之间没有显著差异。
我们的研究结果表明，个体 CPR Z 分数和 CPR Z 分数的变化幅度和方向都可以识别有各种不良围产结局风险的妊娠。然而，35-37 孕周的 CPR Z 分数似乎是更好的预测指标。版权所有 © 2016 ISUOG。由 John Wiley & Sons Ltd 出版。
