The relationship between intrapartum cerebroplacental ratio and adverse perinatal outcomes in term fetuses

Gestational age at birth, birth weight, and gestational age when intrauterine brain sparing occurs determines the neonatal outcome in growth-restricted infants born before 32 weeks of gestation: a retrospective cohort analysis

Background

Preterm birth and fetal growth restriction are the main determinants of perinatal mortality. In the absence of therapeutic interventions, management is restricted to the observation of fetal growth and fetoplacental perfusion to determine the timing of delivery. Fetal circulatory redistribution, known as "brain sparing," represents a sign of fetal hypoxia and has been implemented in algorithms for when to deliver. In the absence of any other option, the nitric oxide donor pentaerythrityl tetranitrate (PETN), which has been shown to improve fetoplacental flow and reduce preterm birth in high-risk patients, is offered to patients as a personal therapy attempt. The aim of this study was to evaluate determinants related to pregnancy, including PETN intake during pregnancy, on immediate neonatal outcomes in a cohort of growth-restricted infants born before 32 completed weeks of gestation.

Methods

We performed a retrospective cohort study of 98 infants born with a birth weight below the 10th percentile before 32 completed weeks of gestation at our tertiary care center between 2010 and 2019. PETN was offered to all mothers with a history of severe adverse pregnancy outcomes who were at high risk of developing fetal growth restriction as an individual therapy attempt.

Results

The mean gestational age at birth was 188.5 days, and the mean birth weight was 549 g, corresponding to a median percentile of three. In 73 (79.3%) cases, brain sparing occurred during pregnancy. A total of 22 (22.4%) neonates were stillborn, 20 died postnatally, and 37.3% developed a severe complication. Multivariable analysis revealed birth weight percentile, gestational age at birth, and gestational age when brain sparing first occurred to be robust predictors of mortality or severe neonatal morbidity. In 39 neonates of mothers taking PETN, this impact of brain sparing was not observed.

Conclusion

Our study is the first to demonstrate a significant association between the early occurrence of brain-sparing and severe neonatal outcomes in a cohort of very early preterm, growth-restricted newborns. The data suggest that PETN intake may ameliorate the effect of brain sparing in the affected neonates.

How to Reach the Best Ultrasound Performance in the Delivery Room

Ultrasonography is an instrument that is present in the maternal-fetal assessment throughout pregnancy and with widely documented benefits, but its use in intrapartum is becoming increasingly relevant. From the assessment of labor progression to the assessment of placental disorders, ultrasound can be used to correlate with physiological findings and physical examination, as its benefit in the delivery room cannot yet be proven. There are still few professionals with adequate training for its use in the delivery room and for the correct interpretation of data. Thus, this article aims to present a review of the entire applicability of ultrasound in the delivery room, considering the main stages of labor. There is still limited research in evidence-based medicine of its various possible uses in intrapartum, but it is expected that further studies can bring improvements in the quality of maternal and neonatal health during labor.

Association of the Cerebro-Placental Ratio With Adverse Outcomes in Pregnancies Affected by Gestational Diabetes Mellitus

OBJECTIVES

Cerebro-placental ratio (CPR) is a doppler tool contributes to clinical decision-making in pregnancies affected by small for gestational age weight (SGA). Pregnancies affected by gestational diabetes mellitus (GDM) tend to have higher newborn weight, but greater risk of adverse perinatal outcomes. We hypothesized that in GDM-complicated-pregnancies CPR will be associated with adverse perinatal outcomes even in the absence of SGA.

METHODS

This prospective single-center cohort study included non-anomalous singleton pregnancies in women with GDM. Those with pre-pregnancy diabetes mellitus, hypertensive disorder or suspected SGA were excluded. Routine fetal sonographic assessment included CPR-defined as middle cerebral artery pulsatilty index/umbilical artery pulsatilty index. Masked CPR measurement closest to birth was used, classified as >10th (normal) or ≤10th centile (low). Primary outcome was a composite, consisting of stillbirth, Caesarean birth due to abnormal fetal heart rate pattern, 5-minute Apgar <7, cord arterial pH < 7.0, hypoxic ischemic encephalopathy, or NICU admission >24 hours.

RESULTS

Of 281 participants, 24 (8.5%) had low CPR, at a mean gestational age of 36.3 weeks (IQR 34.0-37.4). Birthweight percentile was significantly lower among the low CPR group (35th [IQR 16-31] versus 60th [IQR 31-82]; P = .002). There was no statistically difference in the primary composite outcome between the groups (8.3% versus 7.0%, P = .68). Low CPR was significantly associated with a higher risk of neonatal hypoglycemia (adjusted odds ratio 3.2, 95% CI 1.2-8.3).

CONCLUSION

In pregnancies affected by GDM, CPR ≤10th percentile was not associated with adverse perinatal outcome but was associated with neonatal hypoglycemia.

Cerebroplacental ratio prediction of intrapartum fetal compromise according to the interval to delivery

Objectives To evaluate whether the interval to delivery modifies the predictive accuracy of the cerebroplacental ratio (CPR) for the prediction of cesarean section for intrapartum fetal compromise (CS-IFC), either as a single marker or combined with estimated fetal weight centile (EFWc), type of labor onset (TLO) and other clinical variables. Material and methods This was a multicenter retrospective study of 5193 women with singleton pregnancies who underwent an ultrasound scan at 35+0- 41+0 weeks and gave birth within one month of examination, at any of the participating hospitals in Spain, UK, and Italy. CS-IFC was diagnosed in case of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH<7.20, requiring urgent cesarean section. The diagnostic ability of CPR in multiples of the median (CPR MoM) was evaluated at different intervals to delivery, alone and combined with EFWc, TLO, and other pregnancy data such as maternal age, maternal body mass index, parity, and fetal sex, for the prediction of CS-IFC by means of ROC curves and logistic regression analysis. Results The predictive ability of CPR MoM for CS-IFC worsened with the interval to delivery. In general, the best prediction was obtained prior to labor, and adding information related with EFWc and TLO [AUC 0.71 (95% CI 0.64-0.79), 0.73 (95% CI 0.66-0.80) and 0.75 (95% CI 0.69-0.81); P<0.0001]. Addition of more clinical data did not improve prediction. In addition, results did not vary when only cases with spontaneous onset of labor were studied. Conclusion CPR MoM prediction of CS-IFC at the end of pregnancy worsens with the interval to delivery. Accordingly, it should be done in the short term and considering EFWc and TLO.

Middle Cerebral Artery-to-Uterine Artery Pulsatility Index Ratio and Cerebroplacental Ratio Independently Predict Adverse Perinatal Outcomes in Pregnancies at Term

This study aimed to investigate potential predictors, including the cerebroplacental ratio and the middle cerebral artery (MCA)-uterine artery pulsatility index (PI) ratio, for adverse perinatal outcomes in pregnancies at term. This was an observational, prospective study of recruited pregnancies at term. The data were extracted from the medical records in hospital. An adverse perinatal outcome was set as the primary observational endpoint. The receiver operating characteristic curve was plotted to investigate the predictive and cutoff values of risk factors for adverse perinatal outcomes. Univariate and multivariate logistic regression analyses evaluated independent risk factors (maternal, neonatal, prenatal ultrasound and Doppler variables) for adverse perinatal outcomes. There were 392 pregnancies at term included in the study, with 19.4% experiencing adverse perinatal outcomes. The MCA-uterine artery PI ratio was a good predictor of adverse perinatal outcomes by receiver operating characteristic curve analysis (area under the curve = 0.886, p < 0.001), and the cerebroplacental ratio (odds ratio, 0.42; 95% confidence interval, 0.20-0.93; p = 0.032) and MCA-uterine artery PI ratio (odds ratio, 0.25; 95% confidence interval, 0.16-0.42; p = 0.032) were two independent risk factors for adverse perinatal outcomes by univariate and multivariate logistic regression analyses. Notably, both MCA-uterine artery PI ratio and cerebroplacental ratio are significant predictors of adverse perinatal outcome in pregnancies at term.

The Diagnostic Ability of the Cerebroplacental Ratio for the Prediction of Adverse Perinatal Outcome and Intrapartum Fetal Compromise within One Day of Delivery

OBJECTIVES

The objectives of this study were to evaluate the diagnostic abilities of the cerebroplacental ratio (CPR) for the prediction of adverse perinatal outcome (APO) and cesarean section for intrapartum fetal compromise (CS-IFC) within 1 day of delivery.

DESIGN

Retrospective observational case-control study.

METHODS

This was a study of 254 high-risk fetuses attending the day hospital unit of a tertiary referral hospital that underwent an ultrasound examination at 32-41 weeks and gave birth within 1 day of examination. APO was defined as a composite of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20 requiring urgent cesarean section, neonatal umbilical cord pH <7.10, 5-min Apgar score <7, and postpartum admission to neonatal or pediatric intensive care units. CS-IFC was defined in case of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20 requiring urgent cesarean section. The diagnostic ability of CPR for the prediction of APO and CS-IFC was calculated alone and in combination with estimated fetal weight and gestational clinical parameters, including the type of labor onset, using ROC curves and logistic regression analysis.

RESULTS

CPR in multiples of the median (MoM) was a moderate predictor of APO (area under the curve [AUC] = 0.77, p < 0.0001) and CS-IFC (AUC = 0.82, p < 0.0001). The predictive abilities of the multivariable model for APO (AUC = 0.81, p < 0.0001) and CS-IFC (AUC = 0.82, p < 0.0001) did not differ from those of CPR alone .

LIMITATIONS

The small number of cases and the scarcity of information concerning labor induction.

CONCLUSION

In high-risk pregnancies, CPR MoM is a moderate predictor of APO and CS-IFC when performed within 24 h of delivery.

Second trimester cerebroplacental ratio versus umbilicocerebral ratio for the prediction of adverse perinatal outcomes

INTRODUCTION

An abnormal third trimester cerebroplacental ratio has been previously associated with adverse perinatal outcome. The less studied inverse of the cerebroplacental ratio, the umbilicocerebral ratio, has been proposed as a better predictor of adverse perinatal outcome. However, little is known about the implication of either an abnormal cerebroplacental ratio or umbilicocerebral ratio in the second trimester. The objective of this study was to evaluate the relationship between an abnormal second trimester cerebroplacental ratio and adverse perinatal outcome and provide comparison to an abnormal second trimester umbilicocerebral ratio.

MATERIALS AND METHODS

This retrospective cohort study in a single tertiary referral center utilized data from all non-anomalous singleton pregnancies that underwent Doppler assessment of the cerebroplacental ratio between 20 and 28 weeks gestation. The study period was 1 January 2015 to 31 July 2018. Abnormal cerebroplacental ratio was defined as less than the 5th percentile for gestational age. If patients had more than one ultrasound during the study period (i.e. for serial assessment of fetal growth), the lowest value of the cerebroplacental ratio was recorded. The primary outcome was a composite of clinically relevant adverse perinatal outcomes including preterm delivery, small for gestational age, and neonatal intensive care unit admission. Secondary outcomes included urgent delivery for fetal distress (operative vaginal delivery or cesarean section) and hypertensive disorders of pregnancy. An abnormal umbilicocerebral ratio was defined as greater than 95th percentile for gestational age. Areas under the curve were calculated and compared for cerebroplacental ratio and umbilicocerebral ratio.

RESULTS

2326 pregnancies met inclusion criteria. Of these, 91 (3.9%) had an abnormal second trimester cerebroplacental ratio. Fetuses with an abnormal second trimester cerebroplacental ratio had a 2.3-fold (95% CI 1.5-3.6, p < .05) increased risk of adverse perinatal outcome after adjusting for potential confounders such as chronic hypertension, pregestational diabetes, and smoking during pregnancy. Significantly increased risks of preterm delivery (OR 2.0, 95% CI 1.1-38, p < .05) and neonatal intensive care unit admission (OR 2.1, 95% CI 1.2-3.6, p < .05) were also seen in a subgroup analysis of abnormal cerebroplacental ratio in appropriate for gestational age infants. 132 (5.7%) fetuses had an abnormal second trimester umbilicocerebral ratio, and these fetuses had a 2.0-fold (95% CI 1.4-3.0, p < .05) increased risk of adverse perinatal outcome. The area under the curve for CPR and UCR for prediction of the primary outcome was 0.6 for both (95% CI 0.57-0.61 and 0.57-0.62, respectively, both p < .05).

CONCLUSION

An abnormal second trimester cerebroplacental ratio or umbilicocerebral ratio is associated with adverse perinatal outcome. However, the predictive ability of either ratio remains suboptimal.

Clinical significance of cerebroplacental ratio

PURPOSE OF REVIEW

Two-thirds of the pregnancies complicated by stillbirth demonstrate growth restriction. Identification of the foetus at risk of growth restriction is essential to reduce the risk of stillbirth. The aim of this review is to critically appraise the current evidence regarding clinical utility of cerebroplacental ratio (CPR) in antenatal surveillance.

RECENT FINDINGS

The CPR has emerged as an assessment tool for foetuses at increased risk of growth disorders. CPR is a better predictor of adverse events compared with middle-cerebral artery or umbilical artery Doppler alone. The predictive value of CPR for adverse perinatal outcomes is better for suspected small-for-gestational age foetuses compared with appropriate-for-gestational age (AGA) foetuses. CPR could be useful for the risk stratification of small-for-gestational age foetuses to determine the timing of delivery and also to calculate the risk of intrapartum compromise or prolonged admission to the neonatal care unit. Although there are many proposed cut-offs for an abnormal CPR value, evidence is currently lacking to suggest the use of one cut-off over another. CPR appears to be associated with increased risk of intrapartum foetal compromise, abnormal growth velocity, and lower birthweight in AGA foetuses as well. Moreover, birthweight differences are better explained with CPR compared to other factors such as ethnicity. However, the role of CPR in predicting adverse perinatal outcomes such as acidosis or low Apgar scores in AGA foetuses is yet to be determined.

SUMMARY

CPR appears to be a useful surrogate of suboptimal foetal growth and intrauterine hypoxia and it is associated with a variety of perinatal adverse events.