Abstract
ObjectiveTo investigate if cerebroplacental ratio (CPR) adds to the predictive value of umbilical artery pulsatility index (UA PI) alone – standard of practice – for adverse perinatal outcome in singleton pregnancies.Design and settingMeta‐analysis based on individual participant data (IPD).Population or sampleTen centres provided 17 data sets for 21 661 participants, 18 731 of which could be included. Sample sizes per data set ranged from 207 to 9215 individuals. Patient populations varied from uncomplicated to complicated pregnancies.MethodsIn a collaborative, pooled analysis, we compared the prognostic value of combining CPR with UA PI, versus UA PI only and CPR only, with a one‐stage IPD approach. After multiple imputation of missing values, we used multilevel multivariable logistic regression to develop prediction models. We evaluated the classification performance of all models with receiver operating characteristics analysis. We performed subgroup analyses according to gestational age, birthweight centile and estimated fetal weight centile.Main outcome measuresComposite adverse perinatal outcome, defined as perinatal death, caesarean section for fetal distress or neonatal unit admission.ResultsAdverse outcomes occurred in 3423 (18%) participants. The model with UA PI alone resulted in an area under the curve (AUC) of 0.775 (95% CI 0.709–0.828) and with CPR alone in an AUC of 0.778 (95% CI 0.715–0.831). Addition of CPR to the UA PI model resulted in an increase in the AUC of 0.003 points (0.778, 95% CI 0.714–0.831). These results were consistent across all subgroups.ConclusionsCerebroplacental ratio added no predictive value for adverse perinatal outcome beyond UA PI, when assessing singleton pregnancies, irrespective of gestational age or fetal size.Tweetable abstractDoppler measurement of cerebroplacental ratio in clinical practice has limited added predictive value to umbilical artery alone.
Highlights
The cerebroplacental ratio (CPR) is calculated as the ratio of middle cerebral artery (MCA) to umbilical artery (UA) pulsatility index (PI) values, measured by Doppler ultrasound.[11]
High UA PI values and low MCA PI values are associated with adverse outcomes
It currently remains unclear whether assessment of CPR adds value to measuring only UA PI and, if so, how well CPR performs in different subpopulations, such as fetal growth restriction (FGR) versus normal fetal size.[14]
Summary
Fetoplacental Doppler ultrasound is the most widespread method of fetal monitoring, next to cardiotocography, aiming to predict adverse perinatal outcome.[1,2] Currently, ultrasonic assessment of the cerebroplacental ratio (CPR) is becoming widely introduced in clinical practice.[3,4] This test has gained increasing popularity, as shown by the fact that no fewer than six reviews have been published on the subject over the past 3 years.[5,6,7,8,9,10] It has been ascribed specific potential in detecting late-onset fetal growth restriction (FGR).[3,5]The CPR is calculated as the ratio of middle cerebral artery (MCA) to umbilical artery (UA) pulsatility index (PI) values, measured by Doppler ultrasound.[11]. Fetoplacental Doppler ultrasound is the most widespread method of fetal monitoring, next to cardiotocography, aiming to predict adverse perinatal outcome.[1,2] Currently, ultrasonic assessment of the cerebroplacental ratio (CPR) is becoming widely introduced in clinical practice.[3,4] This test has gained increasing popularity, as shown by the fact that no fewer than six reviews have been published on the subject over the past 3 years.[5,6,7,8,9,10] It has been ascribed specific potential in detecting late-onset fetal growth restriction (FGR).[3,5]. The available evidence of CPR and MCA PI is, based on a wide range of observational studies, with variable results but most showing an association between low CPR and adverse perinatal outcome.[8,13] It currently remains unclear whether assessment of CPR adds value to measuring only UA PI and, if so, how well CPR performs in different subpopulations, such as FGR versus normal fetal size.[14]
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