Cerebroplacental ratio in pregnancies complicated by gestational diabetes mellitus

Insulin Use During Gestational and Pre-existing Diabetes in Pregnancy: A Systematic Review of Study Design

INTRODUCTION

Insulin is the first-line pharmacologic therapy for women with diabetes in pregnancy. However, conducting well-designed randomized clinical trials (RCTs) and achieving recommended glycemic targets remains a challenge for this unique population. This systematic literature review (SLR) aimed to understand the evidence for insulin use in pregnancy and the outcome metrics most often used to characterize its effect on glycemic, maternal and fetal outcomes in gestational diabetes mellitus (GDM) and in pregnant women with diabetes.

METHODS

An SLR was conducted using electronic databases in Medline, EMBASE via Ovid platform, evidence-based medicine reviews (2010-2020) and conference proceedings (2018-2019). Studies were included if they assessed the effect of insulin treatment on glycemic, maternal or fetal outcomes in women with diabetes in pregnancy. Studies on any type of diabetes other than gestational or pre-existing diabetes as well as non-human studies were excluded.

RESULTS

In women diagnosed with GDM or pre-existing diabetes, most studies compared treatment of insulin with metformin (n = 35) followed by diet along with lifestyle intervention (n = 24) and glibenclamide (n = 12). Most studies reporting on glycemic outcomes compared insulin with metformin (n = 22) and glibenclamide (n = 4). Fasting blood glucose was the most reported clinical outcome of interest. Among the studies reporting maternal outcomes, method of delivery and delivery complications were most commonly reported. Large for gestational age, stillbirth and perinatal mortality were the most common fetal outcomes reported.

CONCLUSION

This SLR included a total of 108 clinical trials and observational studies with diverse populations and treatment arms. Outcomes varied across the studies, and a lack of consistent outcome measures to manage diabetes in pregnant women was observed. This elucidates a need for global consensus on study design and standardized clinical, maternal and fetal outcomes metrics.

Fetal Splenic Artery Pulsatility Index May Predict the Need for Neonatal Intensive Care in Gestational Diabetes Class A1 Cases

The fetal splenic artery pulsatility index is a parameter that reflects fetal well-being and has been used as a predictor of adverse pregnancy outcomes. The aim of this study was to investigate the predictive value of the splenic artery pulsatility index in gestational diabetes mellitus class A1 cases for intensive care unit admission. In this prospective case-controlled study, only sixty single pregnancy cases diagnosed with gestational diabetes mellitus class A1 were evaluated. Fetal splenic artery Doppler parameters such as peak systolic velocity, pulsatility index, resistivity index, and end-diastolic velocity were measured in all cases. The rate of requirements for the neonatal intensive care unit was noted. In cases requiring fetal intensive care, the fetal splenic pulsatility index was found to be statistically significantly lower than in healthy cases without it (0.94 ± 0.29 vs. 1.70 ± 0.53, respectively, p < 0.001, Student's t-test). When the fetal splenic PI cutoff value was selected as 1.105 cm3, the sensitivity was calculated as 97.9% and the specificity as 58.3% for predicting the need for fetal intensive care (AUC 0.968, p < 0.001, 95% CI 0.929-0.998). The use of a low fetal splenic artery PI parameter is a significant and good indicator for predicting the need for fetal intensive care according to the binary logistic regression analysis result (p = 0.006). This study suggests that evaluation of fetal splenic artery Doppler in mothers with gestational diabetes mellitus may be used to predict neonates requiring a newborn intensive care unit. Therefore, it is recommended that obstetricians use this simple, rapid, and valuable evaluation of fetal splenic artery Doppler and alert the neonatologist that a newborn intensive care unit may be required.

Prognostic Accuracy of Antenatal Doppler Ultrasound Measures in Predicting Adverse Perinatal Outcomes for Pregnancies Complicated by Diabetes: A Systematic Review

OBJECTIVE

This study aimed to assess the prognostic accuracies of Doppler ultrasound measures in predicting adverse perinatal outcomes for pregnancies complicated with preexisting or gestational diabetes mellitus.

DATA SOURCES

An online database search of MEDLINE, Cochrane, Embase, CINAHL, Scopus, and Emcare from inception to April 2022 was conducted.

STUDY ELIGIBILITY CRITERIA

Studies reporting singleton, nonanomalous fetuses of women with either preexisting (type 1 or 2 diabetes mellitus) or gestational diabetes mellitus during pregnancy were included. In addition, the included studies assessed cerebroplacental ratio and middle cerebral artery and/or umbilical artery pulsatility index in the prediction of either: preterm birth, cesarean delivery for fetal distress, APGAR (Appearance, Pulse, Grimace, Activity, and Respiration) score <7 at 5 minutes, neonatal intensive care unit admission (>24 hours), acute respiratory distress syndrome, jaundice, hypoglycemia, hypocalcemia, or neonatal death.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed and 610 articles were identified, of which 15 were included. Two authors independently extracted prognostic data from each article and assessed the study applicability and risk of bias using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) scoring criteria.

RESULTS

A total of 15 studies were included in the review and comprised prospective (n=10; 66%) and retrospective (n=5; 33%) cohorts. Sensitivity and positive predictive values varied widely across each Doppler measurement. Umbilical artery sensitivities were higher than those of cerebroplacental ratio and middle cerebral artery for hypoglycemia, jaundice, neonatal intensive care unit admission, respiratory distress, and preterm birth. Cerebroplacental ratio was the most reported index test; however, prognostic accuracy was worse than that of umbilical artery and middle cerebral artery Doppler across all adverse perinatal outcomes. Significant risk of bias was present in 14 (94%) studies, with substantial heterogeneity observed across studies in terms of study design and outcomes assessed.

CONCLUSION

Abnormal umbilical artery pulsatility index may be of more clinical value in predicting adverse perinatal outcomes compared with cerebroplacental ratio and middle cerebral artery pulsatility index in diabetic pregnancies. Further evaluation of umbilical artery Doppler measurements in diabetic pregnancies using standardized variables across studies is required for broader clinical application. The significant association between abnormal Doppler measurement and hypoglycemia may warrant further investigation.

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.

Ultrasound predictors of adverse outcome in pregnancy complicated by pre-existing and gestational diabetes

INTRODUCTION

Ultrasound assessment of fetuses subjected to hyperglycemia is recommended but, apart from increased size, little is known about its interpretation, and the identification of which large fetuses of diabetic pregnancy are at risk is unclear. Newer markers of adverse outcomes, abdominal circumference growth velocity and cerebro-placental ratio, help to predict risk in non-diabetic pregnancy. Our study aims to assess their role in pregnancies complicated by diabetes.

MATERIAL AND METHODS

This is a retrospective analysis of a cohort of singleton, non-anomalous fetuses of women with pre-existing or gestational diabetes mellitus, and estimated fetal weight at the 10th centile or above. Gestational diabetes was diagnosed by selective screening of at risk groups. A universal ultrasound scan was offered at 20 and 36 weeks of gestation. Estimated fetal weight, abdominal circumference growth velocity, presence of polyhydramnios, and cerebro-placental ratio were evaluated at the 36-week scan. A composite adverse outcome was defined as the presence of one or more of perinatal death, arterial cord pH less than 7.1, admission to Neonatal Unit, 5-minute Apgar less than 7, severe hypoglycemia, or cesarean section for fetal compromise. A chi-squared test was used to test the association of estimated fetal weight at the 90th centile or above, polyhydramnios, abdominal circumference growth velocity at the 90th centile or above, and cerebro-placental ratio at the 5th centile or below with the composite outcome. Logistic regression was used to assess which ultrasound markers were independent risk factors. Odds ratios of composite adverse outcome with combinations of independent ultrasound markers were calculated.

RESULTS

A total of 1044 pregnancies were included, comprising 87 women with pre-existing diabetes mellitus and 957 with gestational diabetes. Estimated fetal weight at the 90th centile or above, abdominal circumference growth velocity at the 90th centile or above, cerebro-placental ratio at the 5th centile or below, but not polyhydramnios, were significantly associated with adverse outcomes: odds ratios (95% confidence intervals) 1.85 (1.21-2.84), 1.54 (1.02-2.31), 1.92 (1.21-3.30), and 1.53 (0.79-2.99), respectively. Only estimated fetal weight at the 90th centile or above and cerebro-placental ratio at the 5th centile or below were independent risk factors. The greatest risk (odds ratio 6.85, 95% confidence interval 2.06-22.78) was found where both the estimated fetal weight is at the 90th centile or above and the cerebro-placental ratio is at the 5th centile or below.

CONCLUSIONS

In diabetic pregnancies, a low cerebro-placental ratio, particularly in a macrosomic fetus, confers additional risk.

Altered Doppler velocimetry of fetal middle cerebral artery in singleton pregnancies complicated by mild well-controlled gestational diabetes

Introduction The aim the present study is to evaluate fetal umbilical artery (UA) and middle cerebral artery (MCA) blood flow in patients with gestational diabetes (GD), in order to determine whether minimal anomalies of glucose metabolism may influence fetal placental function. Methods UA and MCA flow were prospectively measured by transabdominal ultrasound in singleton pregnancies between 34 and 37 weeks of gestation. Results The study included 35 women with GD and 217 non-diabetic patients. Middle cerebral pusatility index (PI) was significantly higher in the GD group (mean MCA - PI =1.82±0.27 vs 1.71 ±0.26; p< 0.02). Likewise, MCA peak systolic velocity (MCA-PSV) was higher in the GD group compared to the non-GD group, though the difference was not significant (mean of MCA-PSV =47.14 ±8.45 vs 47.09 ± 11.21; p = 0.98). UA-PI resulted higher in the non-GD group without significant differences (mean of UA-PI =0.88 ±0.14 vs 0.86 ± 0.15; p = 0.32) Conclusions Our study shows that even in cases of minimal metabolic derangements, GD is characterised by a significant variation in fetal Doppler velocimetry, particularly in the brain.

Fetal cerebral three-dimensional power Doppler vascularization indices and their relationships with maternal glucose levels in pregnancies complicated with gestational diabetes

OBJECTIVES

We aimed to evaluate fetal cerebral circulation using three-dimensional power Doppler (3DPD) vascular indices and to study their relationships with maternal lipid and glycaemic profiles.

METHODS

Case-control study in women with and without gestational diabetes mellitus (GDM) at 28-32 weeks in which feto-maternal Doppler study and 3DPD cerebral vascularization indices (FI, VI and VFI) were determined. Maternal lipid and glycaemic profiles were also analysed. Both groups were compared and the correlations of the 3DPD indices with studied variables were analysed.

RESULTS

There were significant differences between groups in cerebral FI (p= 0.02), mean maternal Uterine artery PI (p= 0.009) and glucose levels (p= 0.001), being higher in the GDM group. Significant negative correlations were found in GDM group between VFI and MCA PI (p = 0.02) and between VI and MCA PI (p= 0.01). In the GDM group we found a negative significant correlation between FI, VI, VFI and maternal glucose (r= -0.52, p<0.001; r= -0.32, p=0.03 and r= -0.36, p= 0.01, respectively).

CONCLUSIONS

Fetal cerebral FI values were higher in GDM pregnancies. All 3DPD vascular indices showed an inverse correlation with maternal glucose levels. These findings support the view that GDM may also represent a fetal vascular disorder influencing fetal neurodevelopment.

Longitudinal change in cerebroplacental ratio in small-for-gestational-age fetuses and risk of stillbirth

OBJECTIVE

To investigate whether assessment of longitudinal change in Doppler variables in small-for-gestational-age (SGA) fetuses improves the prediction of those at risk of stillbirth.

METHODS

This was a longitudinal study of two cohorts of singleton pregnancies, which included SGA and appropriate-for-gestational-age (AGA) fetuses, respectively. The inclusion criteria for the SGA cohort were singleton pregnancy at ≥ 20 weeks' gestation, classified as SGA (estimated fetal weight < 10^th centile). The AGA cohort consisted of singleton pregnancies deemed at high risk of being SGA, which were followed up longitudinally but remained AGA. Fetal middle cerebral artery (MCA) pulsatility index (PI) and umbilical artery (UA)-PI were measured longitudinally and cerebroplacental ratio (CPR) was calculated, and values were converted to multiples of the median. The last two measurements prior to delivery were included in the analysis. Longitudinal models for Doppler variables were developed using linear-mixed models and their accuracy in the prediction of stillbirth was tested using generalized linear models. A Bayesian framework was employed to compare the accuracy of longitudinal and standard (last-scan measurement) models.

RESULTS

In total, 1549 AGA and 941 SGA pregnancies were included in the analysis. There were 30 (3.2%) and no stillbirth cases in the SGA and AGA groups, respectively. Change in MCA-PI, UA-PI and CPR with advancing gestation was significantly different between liveborn AGA and SGA fetuses, with a less pronounced difference with advancing gestation. Using the last measurement, the best models for the prediction of stillbirth in SGA pregnancies were those based on CPR (accuracy, 75.0%; 95% CI, 72.6-77.2%) and UA-PI (accuracy, 71.0%; 95% CI, 68.6-73.4%). The posterior probability of the standard CPR model having a higher accuracy compared with the UA-PI model was 97.2% (magnitude of change (MC), 3.9%; 95% credible interval (CrI), 0.5-7.3%). The accuracies of the standard, compared with the longitudinal, models for UA-PI (71.0% vs 72.8%), MCA-PI (64.6% vs 63.8%) and CPR (75.0% vs 74.9%) in the prediction of stillbirth were not significantly different. The posterior probabilities for improvement in accuracy using longitudinal, compared with standard, assessment were 50.1% (MC, < 0.1%; 95% CrI, -3.3 to 3.3%), 35.2% (MC, -0.1%; 95% CrI, -4.5 to 2.8%) and 82.2% (MC, 1.9%; 95% CrI, -1.5 to 5.3%) for CPR, MCA-PI and UA-PI models, respectively. Therefore, change in Doppler parameters did not improve the accuracy of the prediction of stillbirth, compared with that of the last-scan measurement.

CONCLUSION

Longitudinal assessment of Doppler parameters was not useful in improving the detection of stillbirth in SGA pregnancies, as compared with a single-point assessment. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Cross-validated prediction model for severe adverse neonatal outcomes in a term, non-anomalous, singleton cohort

OBJECTIVE

The aim of this study was to develop a predictive model using maternal, intrapartum and ultrasound variables for a composite of severe adverse neonatal outcomes (SANO) in term infants.

DESIGN

Prospectively collected observational study. Mixed effects generalised linear models were used for modelling. Internal validation was performed using the K-fold cross-validation technique.

SETTING

This was a study of women that birthed at the Mater Mother's Hospital in Brisbane, Australia between January 2010 and April 2017.

PATIENTS

We included all term, non-anomalous singleton pregnancies that had an ultrasound performed between 36 and 38 weeks gestation and had recordings for the umbilical artery pulsatility index, middle cerebral artery pulsatility index and the estimated fetal weight (EFW).

MAIN OUTCOME MEASURES

The components of the SANO were: severe acidosis arterial, admission to the neonatal intensive care unit, Apgar score of ≤3 at 5 min or perinatal death.

RESULTS

There were 5439 women identified during the study period that met the inclusion criteria, with 11.7% of this cohort having SANO. The final generalised linear mixed model consisted of the following variables: maternal ethnicity, socioeconomic score, nulliparity, induction of labour, method of birth and z-scores for EFW and cerebroplacental ratio. The final model had an area under the receiver operating characteristic curve of 0.71.

CONCLUSIONS

The results of this study demonstrate it is possible to predict infants that are at risk of SANO at term with moderate accuracy using a combination of maternal, intrapartum and ultrasound variables. Cross-validation analysis suggests a high calibration of the model.

Doppler ultrasonographic assessment of fetal middle cerebral artery peak systolic velocity in gestational diabetes mellitus

OBJECTIVE

To compare Doppler ultrasonographic measurements of the fetal middle cerebral artery peak systolic velocity (MCA PSV) among women with or without gestational diabetes mellitus (GDM).

METHODS

A cross-sectional study was conducted among pregnant women who presented for prenatal care at a single hospital in Brazil between September 11, 2015, and January 6, 2017. Patients were stratified into a group with GDM and a control group without GDM. One Doppler ultrasonographic assessment was performed per participant. This measurement was made after diagnosis but before the start of treatment among women in the GDM group. Fetal ultrasonographic and biometric variables assessed included MCA PSV, MCA pulsatility index, umbilical artery pulsatility index, the MCA-to-umbilical artery ratio, abdominal circumference, and weight.

RESULTS

The study included 238 women: 115 in the GDM group and 123 in the control group. The median MCA PSV was 1.02 in the GDM group and 1.08 in the control group (P=0.036). No statistically significant between-group differences were found for the other fetal ultrasonographic variables or for the fetal biometric variables assessed. None of the maternal or fetal parameters assessed displayed a linear correlation with MCA PSV.

CONCLUSION

Doppler ultrasonographic measurements of MCA PSV were lowered among the fetuses of women diagnosed with GDM.

Cerebroplacental ratio thresholds measured within 2 weeks before birth and risk of Cesarean section for intrapartum fetal compromise and adverse neonatal outcome

OBJECTIVES

Prediction of intrapartum fetal compromise in uncomplicated, term pregnancies is a global obstetric challenge. Currently, no widely accepted screening test for this condition exists, although the cerebroplacental ratio (CPR) shows promise. We aimed to evaluate prospectively the screening performance of the CPR 10^th centile threshold for prediction of Cesarean section for intrapartum fetal compromise (IFC) and composite adverse neonatal outcome (ANO) after 36 weeks' gestation in low-risk women, and to compare this with CPR ≤ 1 and < 5^th centile thresholds described previously in the literature.

METHODS

This was a blinded, prospective, observational, cohort study of 483 women with uncomplicated singleton pregnancy who underwent fortnightly CPR measurements from 36 weeks to delivery, and their intrapartum and neonatal outcomes were recorded. The CPR 10^th centile threshold screening performance was calculated for emergency Cesarean section for IFC and composite ANO (defined as acidosis at birth, 5-min Apgar score < 7 and/or admission to the neonatal intensive care unit). Comparison of screening performance of CPR ≤ 1 and < 5^th and < 10^th centile thresholds was also undertaken for these specified outcomes.

RESULTS

In total, 437 women were included in the analysis, of whom 4.1% had an emergency Cesarean section for IFC and 17.8% had a composite ANO. Sensitivity and specificity for CPR < 10^th centile were, respectively, 55.6% and 87.9% for prediction of Cesarean section for IFC, and 28.2% and 88.0% for composite ANO. Compared with CPR ≤ 1 and < 5^th centile, CPR < 10^th centile yielded the best overall test performance for detection of Cesarean section for IFC and composite ANO, although its predictive value was only fair for Cesarean section for IFC (area under the receiver-operating characteristics curve (AUC) = 0.72) and poor for composite ANO (AUC = 0.58).

CONCLUSION

The CPR 10^th centile threshold may be useful as a component of a risk assessment tool for Cesarean section for IFC in low-risk pregnancies at term. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Is the fetal cerebroplacental ratio better that the estimated fetal weight in predicting adverse perinatal outcomes in a low risk cohort?

OBJECTIVE

In high-risk pregnancies combining the cerebro-placental ratio (CPR) with the estimated fetal weight (EFW) improves the identification of vulnerable fetuses. The purpose of this study was to assess the CPR and EFW's ability to predict adverse obstetric and perinatal outcomes in a low-risk pregnancy, when measured late in gestation.

METHODS

This was a retrospective study of women who birthed at Mater Mothers Hospitals, Brisbane, Australia between 2010 and 2015. We included all nonanomalous singleton pregnancies that had an ultrasound scan performed between 36 and 38 weeks gestation. Excluded was any major congenital abnormality, aneuploidy, multiple pregnancy, preterm birth, maternal hypertension, or diabetes. The primary outcome was a severe composite neonatal outcome (SCNO) defined as severe acidosis (umbilical cord artery pH <7.0, cord lactate ≥6 mmol/L, cord base excess ≤-12 mmol/L) Apgar score ≤3 at 5 minutes, admission to the neonatal intensive care unit (NICU), and death. A low CPR was defined as <10th centile for gestation and small for gestational age (SGA) was defined as an EFW <10th centile and appropriate for gestational age (AGA) was defined as EFW ≥10th centile.

RESULTS

Of 2425 pregnancies, 13.2% (321/2425) had a fetus with a CPR <10th centile and 13.7% (332/2425) with an EFW <10th centile. Both a low CPR and SGA predicted the SCNO. Individually a low CPR and SGA had sensitivity for detection of SCNO of 23.3% and 24.7%, respectively which increased to 36.7% when combined. Both were associated with emergency caesarean for nonreassuring fetal status (NRFS), as well as early-term birth and admission to NICU. Stratifying the population into EFW <10th centile and EFW ≥10th centile, a low CPR maintained its association with the SCNO, early-term birth and emergency caesarean for NRFS in the cohort with an EFW <10th centile but SCNO lost its association with a low CPR in the EFW >10th cohort. Stratifying the population into CPR <10th centile and CPR >10th centile, a low EFW was associated with early-term birth, induction of labor, admission to NICU, and the SCNO.

CONCLUSIONS

In a low-risk cohort both the CPR and EFW individually and in combination predicts adverse obstetric and perinatal outcomes when measured late in pregnancy. However, the predictive value was enhanced when both were used in combination.