Diagnostic performance of cerebroplacental and umbilicocerebral ratio in appropriate for gestational age and late growth restricted fetuses attempting vaginal delivery: a multicenter, retrospective study

BACKGROUND

Cerebroplacental Doppler studies have been advocated to predict the risk of adverse perinatal outcome (APO) irrespective of fetal weight.

OBJECTIVE

To report the diagnostic performance of cerebroplacental (CPR) and umbilicocerebral (UCR) ratios in predicting APO in appropriate for gestational age (AGA) fetuses and in those affected by late fetal growth restriction (FGR) attempting vaginal delivery.

STUDY DESIGN

Multicenter, retrospective, nested case-control study between 1 January 2017 and January 2020 involving five referral centers in Italy and Spain. Singleton gestations with a scan between 36 and 40 weeks and within two weeks of attempting vaginal delivery were included. Fetal arterial Doppler and biometry were collected. The AGA group was defined as fetuses with an estimated fetal weight and abdominal circumference >10th and <90th percentile, while the late FGR group was defined by Delphi consensus criteria. The primary outcome was the prediction of a composite of perinatal adverse outcomes including either intrauterine death, Apgar score at 5 min <7, abnormal acid-base status (umbilical artery pH < 7.1 or base excess of more than -11) and neonatal intensive care unit (NICU) admission. Area under the curve (AUC) analysis was performed.

RESULTS

646 pregnancies (317 in the AGA group and 329 in the late FGR group) were included. APO were present in 12.6% AGA and 24.3% late FGR pregnancies, with an odds ratio of 2.22 (95% CI 1.46-3.37). The performance of CPR and UCR for predicting APO was poor in both AGA [AUC: 0.44 (0.39-0.51)] and late FGR fetuses [AUC: 0.56 (0.49-0.61)].

CONCLUSIONS

CPR and UCR on their own are poor prognostic predictors of APO irrespective of fetal weight.

Diagnostic performance of cerebroplacental and umbilicocerebral ratio in appropriate for gestational age and late growth restricted fetuses attempting vaginal delivery: a multicenter, retrospective study

BACKGROUND

Cerebroplacental Doppler studies have been advocated to predict the risk of adverse perinatal outcome (APO) irrespective of fetal weight.

OBJECTIVE

To report the diagnostic performance of cerebroplacental (CPR) and umbilicocerebral (UCR) ratios in predicting APO in appropriate for gestational age (AGA) fetuses and in those affected by late fetal growth restriction (FGR) attempting vaginal delivery.

STUDY DESIGN

Multicenter, retrospective, nested case-control study between 1 January 2017 and January 2020 involving five referral centers in Italy and Spain. Singleton gestations with a scan between 36 and 40 weeks and within two weeks of attempting vaginal delivery were included. Fetal arterial Doppler and biometry were collected. The AGA group was defined as fetuses with an estimated fetal weight and abdominal circumference >10th and <90th percentile, while the late FGR group was defined by Delphi consensus criteria. The primary outcome was the prediction of a composite of perinatal adverse outcomes including either intrauterine death, Apgar score at 5 min <7, abnormal acid-base status (umbilical artery pH < 7.1 or base excess of more than -11) and neonatal intensive care unit (NICU) admission. Area under the curve (AUC) analysis was performed.

RESULTS

646 pregnancies (317 in the AGA group and 329 in the late FGR group) were included. APO were present in 12.6% AGA and 24.3% late FGR pregnancies, with an odds ratio of 2.22 (95% CI 1.46-3.37). The performance of CPR and UCR for predicting APO was poor in both AGA [AUC: 0.44 (0.39-0.51)] and late FGR fetuses [AUC: 0.56 (0.49-0.61)].

CONCLUSIONS

CPR and UCR on their own are poor prognostic predictors of APO irrespective of fetal weight.

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

INTRODUCTION

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.

METHODS

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 <7 at 5 min, arterial pH <7.1, base excess of >-11 mEq/mL, or neonatal intensive care unit admission).

RESULTS

Median CPR absolute values (1.11 vs. 1.22, p = 0.018) and centiles (3 vs. 4, p = 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, p = 0.018) and centiles (97 vs. 96, p = 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 <1, UCR >1 or CPR <5th centile, UCR >95th centile) did not improve the diagnostic accuracy.

CONCLUSION

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.

Risk of operative delivery for intrapartum fetal compromise in small-for-gestational-age fetuses at term: external validation of the IRIS algorithm

Objectives: Small-for-gestational-age fetuses (SGA) are at high risk of intrapartum fetal compromise requiring operative delivery. In a recent study, we developed a model using a combination of three antenatal (gestational age at delivery, parity, cerebroplacental ratio) and three intrapartum (epidural use, labor induction and augmentation using oxytocin) variables for the prediction of operative delivery due to presumed fetal compromise in SGA fetuses - the Individual RIsk aSsessment (IRIS) prediction model. The aim of this study was to test the predictive accuracy of the IRIS prediction model in an external cohort of singleton pregnancies complicated by SGA.Methods: This was an external validation study using a cohort of pregnancies from two tertiary referral centers in Spain and England. The inclusion criteria were singleton pregnancies diagnosed with an SGA fetus, defined as estimated fetal weight (EFW) below the 10th centile for gestational age at 36 weeks or beyond, which had fetal Doppler assessment and available data on their intrapartum care and pregnancy outcomes. The main outcome in this study was the operative delivery for presumed fetal compromise. External validation was performed using the coefficients obtained in the original development cohort. The predictive accuracies of models were investigated with receiver operating characteristics (ROC) curves. The Hosmer-Lemeshow test was used to test the goodness-of-fit of models and calibration plots were also obtained for visual assessment. A mobile application using the combined model algorithm was developed to facilitate clinical use.Results: Four hundred twelve singleton pregnancies with an antenatal diagnosis of SGA were included in the study. The operative delivery rate was 22.8% (n = 94). The group which required operative delivery for presumed fetal compromise had significantly fewer multiparous women (19.1 versus 47.8%, p < .001 in the total study population; 19.0 versus 43.5 and 19.2 versus 49.6%, UK and Spain cohort, respectively), lower cerebroplacental ratio (CPR) multiples of median (MoM) (median: 0.77 versus 0.92, p < .001 in the total study population; 0.77 versus 0.92 and 0.77 versus 0.92, UK and Spain cohort, respectively), more inductions of labor (74.5 versus 60.1%, p = .010 in the total study population; 85.7 versus 77.2 and 71.2% and 53.1, UK and Spain cohort, respectively) and more use of oxytocin augmentation (57.4 versus 39.3%, p = .002 in the total study population; 19.0 versus 12.0 and 68.5 and 50.4%, UK and Spain cohort, respectively) compared to those who did not require operative delivery due to presumed fetal compromise. When the original antenatal model was applied to the present cohort, we observed moderate predictive accuracy (AUC: 0.70, 95% CI: 0.64-0.76), and no signs of poor fit (p = .464). The original combined model, when applied to the external cohort, had moderate predictive accuracy (AUC: 0.72, 95% CI: 0.67-0.77) and also no signs of poor fit (p = .268) without the need for refitting. A statistically significant increase in the predictive accuracy was not achieved via refitting of the combined model (AUC 0.76 versus 0.72, p = .060).Conclusions: Using our recently published model, the predictive accuracy for fetal compromise requiring operative delivery in term fetuses thought to be SGA was modest and showed no signs of poor fit in an external cohort. The IRIS tool for mobile devices has been developed to facilitate wide clinical use of this prediction model.Brief rationaleObjective: To determine the external validity of an intrapartum risk prediction model for suspected small-for-gestational age fetuses.What is already known: Small-for-gestational age fetuses are at increased risk of intrapartum compromise. Fetal weight alone is a poor marker for adverse outcomes and a comprehensive prediction model has been previously suggested.What this study adds: Multivariable prediction model showed good accuracy and calibration in this external validation study. The significance of some variables was different between the original and external validation cohort and there was a small margin for improvement with model refitting. A mobile application has been developed to facilitate clinical use.

Risk of operative delivery for intrapartum fetal compromise in small-for-gestational-age fetuses at term: an internally validated prediction model

BACKGROUND

Small-for-gestational-age fetuses are at an increased risk of intrapartum fetal compromise requiring operative delivery. Factors associated with the risk of intrapartum fetal compromise are yet to be established, and a comprehensive model accounting for both the antenatal and intrapartum variables is lacking.

OBJECTIVE

We aimed to develop and validate a predictive model for the risk of operative delivery for presumed intrapartum fetal compromise in fetuses suspected to be small for gestational age at term.

STUDY DESIGN

This was a single-center cohort study of small-for-gestational-age fetuses, defined as estimated fetal weight below the 10th centile in singleton pregnancies at term. The variables included known risk factors for operative delivery because of fetal compromise: maternal characteristics, estimated fetal weight, abdominal circumference, Doppler parameters, gestational age at delivery, induction of labor, and intrapartum risk factors (presence of meconium, augmentation of labor using oxytocin, the use of epidural analgesia, intrapartum pyrexia, and hemorrhage). The receiver-operating characteristics curve analysis was used to investigate the predictive accuracy. Internal validation of the models was performed with bootstrapped data sets.

RESULTS

A total of 927 term pregnancies with 18.7% operative deliveries were included. The antenatal model (area under the curve, 0.69; 95% confidence interval, 0.65-0.73) using only the antenatal risk factors included parity, abdominal circumference centile, gestational age at delivery beyond 39 weeks' gestation, and the cerebroplacental ratio multiples of median. The combined model (area under the curve, 0.76; 95% confidence interval, 0.72-0.80), using both the antenatal and intrapartum risk factors, included the gestational age at delivery beyond 39 weeks' gestation (odds ratio, 1.62; 95% confidence interval, 1.14-2.56), the cerebroplacental ratio multiples of median (odds ratio, 0.38; 95% confidence interval, 0.18-0.79), parity (odds ratio 0.35; 95% confidence interval, 0.22-0.54), induction of labor (odds ratio 1.63; 95% confidence interval, 1.11-2.40), augmentation using oxytocin (odds ratio, 1.84; 95% confidence interval, 1.23-2.73) and the use of epidural analgesia (odds ratio, 2.80; 95% confidence interval, 1.94-4.04). The results indicate that the model has good discrimination and, according to the Hosmer-Lemeshow test, has good fit (P = .591).

CONCLUSION

The prediction model demonstrates 6 important risk factors that are associated with the risk of operative delivery for fetal compromise in small-for-gestational-age fetuses at term. The model shows good discrimination and fit and has the potential to be used for clinical decision making and to counsel women about their individual intrapartum risk.

[Ehlers-Danlos syndrome type III and pregnancy: labor analgesia]

We report the use of obstetrical extradural analgesia in a primigravida with Ehlers-Danlos syndrome type III. Management focused on the possible vascular tissue involvement and the risk of bleeding during the access into the extradural space. The procedure was performed after ruling out the anomalies in the dermis and its vasculature.