Building consensus: thresholds for delivery in TRUFFLE-2 randomized intervention study

Intrauterine Growth Restriction: Need to Improve Diagnostic Accuracy and Evidence for a Key Role of Oxidative Stress in Neonatal and Long-Term Sequelae

Intrauterine growth restriction (IUGR) and being small for gestational age (SGA) are two distinct conditions with different implications for short- and long-term child development. SGA is present if the estimated fetal or birth weight is below the tenth percentile. IUGR can be identified by additional abnormalities (pathological Doppler sonography, oligohydramnion, lack of growth in the interval, estimated weight below the third percentile) and can also be present in fetuses and neonates with weights above the tenth percentile. There is a need to differentiate between IUGR and SGA whenever possible, as IUGR in particular is associated with greater perinatal morbidity, prematurity and mortality, as well as an increased risk for diseases in later life. Recognizing fetuses and newborns being "at risk" in order to monitor them accordingly and deliver them in good time, as well as to provide adequate follow up care to ameliorate adverse sequelae is still challenging. This review article discusses approaches to differentiate IUGR from SGA and further increase diagnostic accuracy. Since adverse prenatal influences increase but individually optimized further child development decreases the risk of later diseases, we also discuss the need for interdisciplinary follow-up strategies during childhood. Moreover, we present current concepts of pathophysiology, with a focus on oxidative stress and consecutive inflammatory and metabolic changes as key molecular mechanisms of adverse sequelae, and look at future scientific opportunities and challenges. Most importantly, awareness needs to be raised that pre- and postnatal care of IUGR neonates should be regarded as a continuum.

A systematic review and critical evaluation of quality of clinical practice guidelines on fetal growth restriction

INTRODUCTION

To systematically identify and critically assess the quality of clinical practice guidelines (CPGs) on management fetal growth restriction (FGR).

CONTENT

Medline, Embase, Google Scholar, Scopus and ISI Web of Science databases were searched to identify all relevant CPGs on FGR.

SUMMARY

Diagnostic criteria of FGR, recommended growth charts, recommendation for detailed anatomical assessment and invasive testing, frequency of fetal growth scans, fetal monitoring, hospital admission, drugs administrations, timing at delivery, induction of labor, postnatal assessment and placental histopathological were assessed. Quality assessment was evaluated by AGREE II tool. Twelve CPGs were included. Twenty-five percent (3/12) of CPS adopted the recently published Delphi consensus, 58.3% (7/12) an estimated fetal weight (EFW)/abdominal circumference (AC) EFW/AC <10th percentile, 8.3% (1/12) an EFW/AC <5th percentile while one CPG defined FGR as an arrest of growth or a shift in its rate measured longitudinally. Fifty percent (6/12) of CPGs recommended the use of customized growth charts to assess fetal growth. Regarding the frequency of Doppler assessment, in case of absent or reversed end-diastolic flow in the umbilical artery 8.3% (1/12) CPGs recommended assessment every 24-48, 16.7% (2/12) every 48-72 h, 1 CPG generically recommended assessment 1-2 times per week, while 25 (3/12) did not specifically report the frequency of assessment. Only 3 CPGs reported recommendation on the type of Induction of Labor to adopt. The AGREE II standardized domain scores for the first overall assessment (OA1) had a mean of 50%.

OUTLOOK

There is significant heterogeneity in the management of pregnancies complicated by FGR in published CPGs.

Management of late-onset fetal growth restriction: pragmatic approach

OBJECTIVES

There is limited prospective evidence to guide the management of late-onset fetal growth restriction (FGR) and its differentiation from small-for-gestational age. The aim of this study was to assess prospectively a novel protocol in which ultrasound criteria were used to classify women with suspected late FGR into two groups: those at low risk, who were managed expectantly until the anticipated date of delivery, and those at high risk, who were delivered soon after 37 weeks of gestation. We also compared the outcome of this prospective cohort with that of a historical cohort of women presenting similarly with suspected late FGR, in order to evaluate the impact of the new protocol.

METHODS

This was a prospective study of women with a non-anomalous singleton pregnancy at ≥ 32 weeks' gestation attending a tertiary hospital in London, UK, between February 2018 and September 2019, with estimated fetal weight (EFW) ≤ 10th centile, or EFW > 10th centile in addition to a decrease in fetal abdominal circumference of ≥ 50 centiles compared with a previous scan, umbilical artery Doppler pulsatility index > 95th centile or cerebroplacental ratio < 5th centile. Women were classified as low or high risk based on ultrasound and Doppler criteria. Women in the low-risk group were delivered by 41 weeks of gestation, unless they subsequently met high-risk criteria, whereas women in the high-risk group (EFW < 3rd centile, umbilical artery Doppler pulsatility index > 95th centile or EFW between 3rd and 10th centiles (inclusive) with abdominal circumference drop or abnormal Dopplers) were delivered at or soon after 37 weeks. The primary outcome was adverse neonatal outcome and included hypothermia, hypoglycemia, neonatal unit admission, jaundice requiring treatment, suspected infection, feeding difficulties, 1-min Apgar score < 7, hospital readmission and any severe adverse neonatal outcome (perinatal death, resuscitation using inotropes or mechanical ventilation, 5-min Apgar score < 7, metabolic acidosis, sepsis, and cerebral, cardiac or respiratory morbidity). Secondary outcomes were adverse maternal outcome (operative delivery for abnormal fetal heart rate) and severe adverse neonatal outcome. Women managed according to the new protocol were compared with a historical cohort of 323 women delivered prior to the implementation of the new protocol, for whom management was guided by individual clinician expertise.

RESULTS

Over 18 months, 321 women were recruited to the prospective cohort, of whom 156 were classified as low risk and 165 were high risk. Adverse neonatal outcome was significantly less common in the low-risk compared with the high-risk group (45% vs 58%; adjusted odds ratio (aOR), 0.6 (95% CI, 0.4-0.9); P = 0.022). There was no significant difference in the rate of adverse maternal outcome (18% vs 24%; aOR, 0.7 (95% CI, 0.4-1.2); P = 0.142) or severe adverse neonatal outcome (3.8% vs 8.5%; aOR, 0.5 (95% CI, 0.2-1.3); P = 0.153) between the low- and high-risk groups. Compared with women in the historical cohort classified retrospectively as low risk, low-risk women managed under the new protocol had a lower rate of adverse neonatal outcome (45% vs 58%; aOR, 0.6 (95% CI, 0.4-0.9); P = 0.026).

CONCLUSIONS

Appropriate risk stratification to guide management of late FGR was associated with a reduced rate of adverse neonatal outcome in low-risk pregnancies. In clinical practice, a policy of expectantly managing women with a low-risk late-onset FGR pregnancy at term could improve neonatal and long-term development. Randomized controlled trials are needed to assess the effect of an evidence-based conservative management protocol for late FGR on perinatal morbidity and mortality and long-term neurodevelopment. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal and 2-year neurodevelopmental outcome in late preterm fetal compromise: the TRUFFLE 2 randomised trial protocol

INTRODUCTION

Following the detection of fetal growth restriction, there is no consensus about the criteria that should trigger delivery in the late preterm period. The consequences of inappropriate early or late delivery are potentially important yet practice varies widely around the world, with abnormal findings from fetal heart rate monitoring invariably leading to delivery. Indices derived from fetal cerebral Doppler examination may guide such decisions although there are few studies in this area. We propose a randomised, controlled trial to establish the optimum method of timing delivery between 32 weeks and 36 weeks 6 days of gestation. We hypothesise that delivery on evidence of cerebral blood flow redistribution reduces a composite of perinatal poor outcome, death and short-term hypoxia-related morbidity, with no worsening of neurodevelopmental outcome at 2 years.

METHODS AND ANALYSIS

Women with non-anomalous singleton pregnancies 32+0 to 36+6 weeks of gestation in whom the estimated fetal weight or abdominal circumference is <10th percentile or has decreased by 50 percentiles since 18-32 weeks will be included for observational data collection. Participants will be randomised if cerebral blood flow redistribution is identified, based on umbilical to middle cerebral artery pulsatility index ratio values. Computerised cardiotocography (cCTG) must show normal fetal heart rate short term variation (≥4.5 msec) and absence of decelerations at randomisation. Randomisation will be 1:1 to immediate delivery or delayed delivery (based on cCTG abnormalities or other worsening fetal condition). The primary outcome is poor condition at birth and/or fetal or neonatal death and/or major neonatal morbidity, the secondary non-inferiority outcome is 2-year infant general health and neurodevelopmental outcome based on the Parent Report of Children's Abilities-Revised questionnaire.

ETHICS AND DISSEMINATION

The Study Coordination Centre has obtained approval from London-Riverside Research Ethics Committee (REC) and Health Regulatory Authority (HRA). Publication will be in line with NIHR Open Access policy.

TRIAL REGISTRATION NUMBER

Main sponsor: Imperial College London, Reference: 19QC5491. Funders: NIHR HTA, Reference: 127 976. Study coordination centre: Imperial College Healthcare NHS Trust, Du Cane Road, London, W12 0HS with Centre for Trials Research, College of Biomedical & Life Sciences, Cardiff University. IRAS Project ID: 266 400. REC reference: 20/LO/0031. ISRCTN registry: 76 016 200.

Ultrasound prediction of adverse perinatal outcome at diagnosis of late-onset fetal growth restriction

OBJECTIVE

To evaluate the relationship between Doppler and biometric ultrasound parameters measured at diagnosis and perinatal adverse outcome in a cohort of late-onset growth-restricted (FGR) fetuses.

METHODS

This was a multicenter retrospective study of data obtained between 2014 and 2019 including non-anomalous singleton pregnancies complicated by late-onset FGR (≥ 32 weeks), which was defined either as abdominal circumference (AC) or estimated fetal weight (EFW) < 10^th percentile for gestational age or as reduction of the longitudinal growth of AC by over 50 percentiles compared to ultrasound scan performed between 18 and 32 weeks of gestation. We evaluated the association between sonographic findings at diagnosis of FGR and composite adverse perinatal outcome (CAPO), defined as stillbirth or at least two of the following: obstetric intervention due to intrapartum fetal distress, neonatal acidemia, birth weight < 3^rd percentile and transfer to the neonatal intensive care unit (NICU).

RESULTS

Overall, 468 cases with complete biometric and umbilical, fetal middle cerebral and uterine artery (UtA) Doppler data were included, of which 53 (11.3%) had CAPO. On logistic regression analysis, only EFW percentile was associated independently with CAPO (P = 0.01) and NICU admission (P < 0.01), while the mean UtA pulsatility index (PI) multiples of the median (MoM) > 95^th percentile at diagnosis was associated independently with obstetric intervention due to intrapartum fetal distress (P = 0.01). The model including baseline pregnancy characteristics and the EFW percentile was associated with an area under the receiver-operating-characteristics curve of 0.889 (95% CI, 0.813-0.966) for CAPO (P < 0.001). A cut-off value for EFW corresponding to the 3.95^th percentile was found to discriminate between cases with and those without CAPO, yielding a sensitivity of 58.5% (95% CI, 44.1-71.9%), specificity of 69.6% (95% CI, 65.0-74.0%), positive predictive value of 19.8% (95% CI, 13.8-26.8%) and negative predictive value of 92.9% (95% CI, 89.5-95.5%).

CONCLUSIONS

Retrospective data from a large cohort of late-onset FGR fetuses showed that EFW at diagnosis is the only sonographic parameter associated independently with the occurrence of CAPO, while mean UtA-PI MoM > 95^th percentile at diagnosis is associated independently with intrapartum distress leading to obstetric intervention. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical interpretation and implementation of the sFlt-1/PlGF ratio in the prediction, diagnosis and management of preeclampsia

Preeclampsia is associated with significant morbidity and mortality for mother and baby. Although around 30% of all pregnancies are evaluated for preeclampsia, diagnosis is difficult, especially in patients who have overlying symptoms from other diseases. Discovery of circulating angiogenic factors in the pathogenesis of preeclampsia has been a major advance for both diagnosis and prognosis. The anti-angiogenic factor, soluble fms-like tyrosine kinase 1 (sFlt-1) and the pro-angiogenic factor, placental growth factor (PlGF), can be measured in plasma and serum and are usually reported as a ratio, which specifically relates to the onset and severity of preeclampsia. The sFlt-1/PlGF ratio has a very high negative predictive value in ruling out the development of preeclampsia within 7 days among women with suspected preeclampsia. Currently, there is no clear consensus on the practical use of angiogenic biomarkers in the detection and management of preeclampsia in routine clinical practice. While major international clinical guidelines exist, they do not define which specific parameters signal patient admission, or outpatient evaluation of suspected preeclampsia, and most clinicians follow local practices. Better guidance is needed on risk stratification among women with suspected preeclampsia, as well as among women at high risk for preeclampsia. Prediction of adverse outcomes in women, after the clinical diagnosis of preeclampsia, is also important. This report has been developed following a meeting of international experts and aims to guide clinicians in the management of pregnant women at risk of preeclampsia using the sFlt-1/PlGF ratio test.

Fetal cerebral blood-flow redistribution: analysis of Doppler reference charts and association of different thresholds with adverse perinatal outcome

OBJECTIVES

First, to compare published Doppler reference charts of the ratios of flow in the fetal middle cerebral and umbilical arteries (i.e. the cerebroplacental ratio (CPR) and umbilicocerebral ratio (UCR)). Second, to assess the association of thresholds of CPR and UCR based on these charts with short-term composite adverse perinatal outcome in a cohort of pregnancies considered to be at risk of late preterm fetal growth restriction.

METHODS

Studies presenting reference charts for CPR or UCR were searched for in PubMed. Formulae for plotting the median and the 10^th percentile (for CPR) or the 90^th percentile (for UCR) against gestational age were extracted from the publication or calculated from the published tables. Data from a prospective European multicenter observational cohort study of singleton pregnancies at risk of fetal growth restriction at 32 + 0 to 36 + 6 weeks' gestation, in which fetal arterial Doppler measurements were collected longitudinally, were used to compare the different charts. Specifically, the association of UCR and CPR thresholds (CPR < 10^th percentile or UCR ≥ 90^th percentile and multiples of the median (MoM) values) with composite adverse perinatal outcome was analyzed. The association was also compared between chart-based thresholds and absolute thresholds. Composite adverse perinatal outcome comprised both abnormal condition at birth and major neonatal morbidity.

RESULTS

Ten studies presenting reference charts for CPR or UCR were retrieved. There were large differences between the charts in the 10^th and 90^th percentile values of CPR and UCR, respectively, while median values were more similar. In the gestational-age range of 28-36 weeks, there was no relationship between UCR or CPR and gestational age. From the prospective observational study, 856 pregnancies at risk of late-onset preterm fetal growth restriction were included in the analysis. The association of abnormal UCR or CPR with composite adverse perinatal outcome was similar for percentile thresholds or MoM values, as calculated from the charts, and for absolute thresholds, both on univariable analysis and after adjustment for gestational age at measurement, estimated fetal weight MoM and pre-eclampsia. The adjusted odds ratio for composite adverse perinatal outcome was 3.3 (95% CI, 1.7-6.4) for an absolute UCR threshold of ≥ 0.9 or an absolute CPR threshold of < 1.11 (corresponding to ≥ 1.75 MoM), and 1.6 (95% CI, 0.9-2.9) for an absolute UCR threshold of ≥ 0.7 to < 0.9 or an absolute CPR threshold of ≥ 1.11 to < 1.43 (corresponding to ≥ 1.25 to < 1.75 MoM).

CONCLUSIONS

In the gestational-age range of 32 to 36 weeks, adjustment of CPR or UCR for gestational age is not necessary when assessing the risk of adverse outcome in pregnancies at risk of fetal growth restriction. The adoption of absolute CPR or UCR thresholds, independent of reference charts, is feasible and makes clinical assessment simpler than if using percentiles or other gestational-age normalized units. The high variability in percentile threshold values among the commonly used UCR and CPR reference charts hinders reliable diagnosis and clinical management of late preterm fetal growth restriction. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Quality control of fetal biometric evaluation and Doppler ultrasound

In recent years quality control in obstetric ultrasound has become recommended and an essential component of obstetric scanning. This is to minimize the inaccuracy and variability related to fetal measurements, to provide an effective quality assurance system to sonographers to certify their practice and decrease the impact of medical litigations. For a quality control system in obstetric ultrasound to be useful clinically, multiple strategies need to be employed: certified training, practical standardization exercise, image storing, qualitative and quantitative quality control. Qualitative quality control consists of the evaluation of images obtained for fetal biometry and Doppler scans using an objective score against predefined criteria. Quantitative quality control consists of analyzing quantitatively the performance of a sonographer and the impact on measurements values. Quantitative analysis could be performed either using estimates of intraobserver or interobserver reproducibility of plane acquisition and caliper placements.

Fetal cerebral Doppler changes and outcome in late preterm fetal growth restriction: prospective cohort study

OBJECTIVES

To explore the association between fetal umbilical and middle cerebral artery (MCA) Doppler abnormalities and outcome in late preterm pregnancies at risk of fetal growth restriction.

METHODS

This was a prospective cohort study of singleton pregnancies at risk of fetal growth restriction at 32 + 0 to 36 + 6 weeks of gestation, enrolled in 33 European centers between 2017 and 2018, in which umbilical and fetal MCA Doppler velocimetry was performed. Pregnancies were considered at risk of fetal growth restriction if they had estimated fetal weight and/or abdominal circumference (AC) < 10^th percentile, abnormal arterial Doppler and/or a fall in AC growth velocity of more than 40 percentile points from the 20-week scan. Composite adverse outcome comprised both immediate adverse birth outcome and major neonatal morbidity. Using a range of cut-off values, the association of MCA pulsatility index and umbilicocerebral ratio (UCR) with composite adverse outcome was explored.

RESULTS

The study population comprised 856 women. There were two (0.2%) intrauterine deaths. Median gestational age at delivery was 38 (interquartile range (IQR), 37-39) weeks and birth weight was 2478 (IQR, 2140-2790) g. Compared with infants with normal outcome, those with composite adverse outcome (n = 93; 11%) were delivered at an earlier gestational age (36 vs 38 weeks) and had a lower birth weight (1900 vs 2540 g). The first Doppler observation of MCA pulsatility index < 5^th percentile and UCR Z-score above gestational-age-specific thresholds (1.5 at 32-33 weeks and 1.0 at 34-36 weeks) had the highest relative risks (RR) for composite adverse outcome (RR 2.2 (95% CI, 1.5-3.2) and RR 2.0 (95% CI, 1.4-3.0), respectively). After adjustment for confounders, the association between UCR Z-score and composite adverse outcome remained significant, although gestational age at delivery and birth-weight Z-score had a stronger association.

CONCLUSION

In this prospective multicenter study, signs of cerebral blood flow redistribution were found to be associated with adverse outcome in late preterm singleton pregnancies at risk of fetal growth restriction. Whether cerebral redistribution is a marker describing the severity of fetal growth restriction or an independent risk factor for adverse outcome remains unclear, and whether it is useful for clinical management can be answered only in a randomized trial. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.