Supplementary Material for: Comparison between Cerebroplacental Ratio and Umbilicocerebral Ratio in Predicting Adverse Perinatal Outcome in Pregnancies Complicated by Late Fetal Growth Restriction: A Multicenter, Retrospective Study

<b><i>Introduction:</i></b> The role of cerebroplacental ratio (CPR) or umbilicocerebral ratio (UCR) to predict adverse intrapartum and perinatal outcomes in pregnancies complicated by late fetal growth restriction (FGR) remains controversial. <b><i>Methods:</i></b> This was a multicenter, retrospective cohort study involving 5 referral centers in Italy and Spain, including singleton pregnancies complicated by late FGR, as defined by Delphi consensus criteria, with a scan 1 week prior to delivery. The primary objective was to compare the diagnostic accuracy of the CPR and UCR for the prediction of a composite adverse outcome, defined as the presence of either an adverse intrapartum outcome (need for operative delivery/cesarean section for suspected fetal distress) or an adverse perinatal outcome (intrauterine death, Apgar score &lt;7 at 5 min, arterial pH &lt;7.1, base excess of &gt;−11 mEq/mL, or neonatal intensive care unit admission). <b><i>Results:</i></b> Median CPR absolute values (1.11 vs. 1.22, <i>p</i> = 0.018) and centiles (3 vs. 4, <i>p</i> = 0.028) were lower in pregnancies with a composite adverse outcome than in those without it. Median UCR absolute values (0.89 vs. 0.82, <i>p</i> = 0.018) and centiles (97 vs. 96, <i>p</i> = 0.028) were higher. However, the area under the curve, 95% confidence interval for predicting the composite adverse outcome showed a poor predictive value: 0.580 (0.512–0.646) for the raw absolute values of CPR and UCR, and 0.575 (0.507–0.642) for CPR and UCR centiles adjusted for gestational age. The use of dichotomized values (CPR &lt;1, UCR &gt;1 or CPR &lt;5th centile, UCR &gt;95th centile) did not improve the diagnostic accuracy. <b><i>Conclusion:</i></b> The CPR and UCR measured in the week prior delivery are of low predictive value to assess adverse intrapartum and perinatal outcomes in pregnancies with late FGR.

<b><i>引言：</i></b> 脑胎盘比值（cerebroplacental ratio, CPR）或脐脑比值（umbilicocerebral ratio, UCR）在预测合并晚期胎儿生长受限（fetal growth restriction, FGR）妊娠的产时不良结局与围产期不良结局中的作用仍存在争议。<b><i>方法：</i></b> 本研究为一项多中心回顾性队列研究，纳入意大利与西班牙5家转诊中心的、符合德尔菲共识标准的晚期FGR单胎妊娠病例，所有受试者均于分娩前1周接受超声检查。本研究首要目的为比较CPR与UCR预测复合不良结局的诊断准确度，复合不良结局定义为存在以下任一情况：产时不良结局（因疑似胎儿窘迫需手术助产或剖宫产），或围产期不良结局（宫内死胎、5分钟Apgar评分＜7、动脉血pH＜7.1、碱剩余＞-11mEq/mL，或需新生儿重症监护病房收治）。<b><i>结果：</i></b> 发生复合不良结局的妊娠受试者，其CPR绝对数值中位数（1.11 vs 1.22，p=0.018）及百分位数中位数（3 vs 4，p=0.028）均低于未发生不良结局的受试者；而UCR绝对数值中位数（0.89 vs 0.82，p=0.018）及百分位数中位数（97 vs 96，p=0.028）则更高。然而，用于预测复合不良结局的曲线下面积及95%置信区间显示其预测价值较低：CPR与UCR的原始绝对数值对应的曲线下面积为0.580（95%置信区间：0.512~0.646），按胎龄校正的CPR与UCR百分位数对应的曲线下面积为0.575（95%置信区间：0.507~0.642）。采用二分法取值（CPR＜1、UCR＞1，或CPR＜第5百分位数、UCR＞第95百分位数）并未提升诊断准确度。<b><i>结论：</i></b> 分娩前1周检测的CPR与UCR，对于合并晚期FGR的妊娠，其评估产时及围产期不良结局的预测价值较低。