Multicentre randomised trial of screening with sFlt1/PlGF and planned delivery to prevent pre-eclampsia at term: protocol of the PE37 study

INTRODUCTION

Pre-eclampsia affects ~5%-7% of pregnancies. Although improved obstetric care has significantly diminished its associated maternal mortality, it remains a leading cause of maternal morbidity and mortality in the world. Term pre-eclampsia accounts for 70% of all cases and a large proportion of maternal-fetal morbidity related to this condition. Unlike in preterm pre-eclampsia, the prediction and prevention of term pre-eclampsia remain unsolved. Previously proposed approaches are based on combined third-trimester screening and/or prophylactic drugs, but these policies are unlikely to be widely implementable in many world settings. Recent evidence shows that the soluble fms-like tyrosine kinase-1 (s-Flt-1) to placental growth factor (PlGF) ratio measured at 35-37 weeks' gestation predicts term pre-eclampsia with an 80% detection rate. Likewise, recent studies demonstrate that induction of labour beyond 37 weeks is safe and well accepted by women. We hypothesise that a single-step universal screening for term pre-eclampsia based on sFlt1/PlGF ratio at 35-37 weeks followed by planned delivery beyond 37 weeks reduces the prevalence of term pre-eclampsia without increasing the caesarean section rates or worsening the neonatal outcomes.

METHODS AND ANALYSIS

We propose an open-label randomised clinical trial to evaluate the impact of a screening of term pre-eclampsia with the sFlt-1/PlGF ratio followed by planned delivery in asymptomatic nulliparous women at 35-37 weeks. Women will be assigned 1:1 to revealed (sFlt-1/PlGF known to clinicians) versus concealed (unknown) arms. A cut-off of >90th centile is used to define the high risk of subsequent pre-eclampsia and offer planned delivery from 37 weeks. The efficacy variables will be analysed and compared between groups primarily following an intention-to-treat approach, by ORs and their 95% CI. This value will be computed using a Generalised Linear Mixed Model for binary response (study group as fixed effect and the centre as intercept random effect).

ETHICS AND DISSEMINATION

The study is conducted under the principles of Good Clinical Practice. This study was accepted by the Clinical Research Ethics Committee of Hospital Clinic Barcelona on 20 November 2020. Subsequent approval by individual ethical committees and competent authorities was granted. The study results will be published in peer-reviewed journals and disseminated at international conferences.

TRIAL REGISTRATION NUMBER

NCT04766866.

Management of fetal Growth Restriction at term by Angiogenic Factors versus feto-maternal Doppler (GRAFD) to avoid adverse perinatal outcomes: multicenter open-label randomized controlled trial study protocol (Preprint)

Background

Fetal smallness affects 10% of pregnancies. Small fetuses are at a higher risk of adverse outcomes. Their management using estimated fetal weight and feto-maternal Doppler has a high sensitivity for adverse outcomes; however, more than 60% of fetuses are electively delivered at 37 to 38 weeks. On the other hand, classification using angiogenic factors seems to have a lower false-positive rate. Here, we present a protocol for the Fetal Growth Restriction at Term Managed by Angiogenic Factors Versus Feto-Maternal Doppler (GRAFD) trial, which compares the use of angiogenic factors and Doppler to manage small fetuses at term.

Objective

The primary objective is to demonstrate that classification based on angiogenic factors is not inferior to estimated fetal weight and Doppler at detecting fetuses at risk of adverse perinatal outcomes.

Methods

This is a multicenter, open-label, randomized controlled trial conducted in 20 hospitals across Spain. A total of 1030 singleton pregnancies with an estimated fetal weight ≤10th percentile at 36+0 to 37+6 weeks+days will be recruited and randomly allocated to either the control or the intervention group. In the control group, standard Doppler-based management will be used. In the intervention group, cases with a soluble fms-like tyrosine kinase to placental growth factor ratio ≥38 will be classified as having fetal growth restriction; otherwise, they will be classified as being small for gestational age. In both arms, the fetal growth restriction group will be delivered at ≥37 weeks and the small for gestational age group at ≥40 weeks. We will assess differences between the groups by calculating the relative risk, the absolute difference between incidences, and their 95% CIs.

Results

Recruitment for this study started on September 28, 2020. The study results are expected to be published in peer-reviewed journals and disseminated at international conferences in early 2023.

Conclusions

The angiogenic factor–based protocol may reduce the number of pregnancies classified as having fetal growth restriction without worsening perinatal outcomes. Moreover, reducing the number of unnecessary labor inductions would reduce costs and the risks derived from possible iatrogenic complications. Additionally, fewer inductions would lower the rate of early-term neonates, thus improving neonatal outcomes and potentially reducing long-term infant morbidities.

Trial Registration

ClinicalTrials.gov NCT04502823; https://clinicaltrials.gov/ct2/show/NCT04502823

International Registered Report Identifier (IRRID)

DERR1-10.2196/37452

Effectiveness of ultrasound screening for placenta accreta spectrum using standard ultrasound criteria in a secondary care setting

OBJECTIVES

Ultrasound detection of placenta accreta spectrum (PAS) among women at risk is a key goal to reduce obstetric morbidity, but there is scarce information of its performance in real clinical settings. We report the effectiveness of a standardized ultrasound protocol to detect PAS in women with placenta previa in a secondary-level hospital.

METHODS

A retrospective analysis, including a cohort of 126 women with persistent placenta previa among 27,975 pregnancies between 2008 and 2020. All 126 women underwent standardized transabdominal and transvaginal ultrasound assessing 5 criteria: 1) loss of hypoechoic retroplacental zone and/or myometrial thinning <1 mm; 2) lacunar images with flow >15 cm/sec; 3) thick and bulging placenta; 4) thinning or interruption of the uterine-bladder serous interface; and 5) placental or uterovesical hypervascularity. The presence of at least one criterion was considered a high-risk for PAS. Diagnosis of PAS was confirmed during caesarean section and by histopathological analysis.

RESULTS

Among 126 women with placenta previa, 11 (8.7%) cases of PAS were diagnosed, of which 10 were detected prenatally by ultrasound. This resulted in a sensitivity of 90,9%, a specificity of 98,3%, a positive predictive value (PPV) of 83,3%, and negative predictive value (NPV) of 99,1%. Histopathological assessment showed six placenta increta (54.5%), four percreta (36.4%) and one accreta (9.1%). All 10 cases of invasive placenta presented more than three ultrasound criteria.

CONCLUSIONS

Standardized ultrasound screening protocol in women at risk due to placenta previa in the third trimester was highly effective in detecting PAS in a secondary-level hospital setting.

Next-Generation Sequencing Gene Panels and "Solo" Clinical Exome Sequencing Applied in Structurally Abnormal Fetuses

OBJECTIVE

The aim of the study was to assess the diagnostic yield of 2 different next-generation sequencing (NGS) approaches: gene panel and "solo" clinical exome sequencing (solo-CES), in fetuses with structural anomalies and normal chromosomal microarray analysis (CMA), in the absence of a known familial mutation.

METHODOLOGY

Gene panels encompassing from 2 to 140 genes, were applied mainly in persistent nuchal fold/fetal hydrops and in large hyperechogenic kidneys. Solo-CES, which entails sequencing the fetus alone and only interpreting the Online Mendelian Inheritance in Man genes, was performed in multisystem or recurrent structural anomalies.

RESULTS

During the study period (2015-2020), 153 NGS studies were performed in 148 structurally abnormal fetuses with a normal CMA. The overall diagnostic yield accounted for 35% (53/153) of samples and 36% (53/148) of the fetuses. Diagnostic yield with the gene panels was 31% (15/49), similar to 37% (38/104) in solo-CES.

CONCLUSIONS

A monogenic disease was established as the underlying cause in 35% of selected fetal structural anomalies by gene panels and solo-CES.

Three-dimensional ultrasonography for advanced neurosonography (neurosofe-3D): Validation of a brain volume acquisition guideline

INTRODUCTION

This study aimed to evaluate the quality of the brain volumes acquired following an evidence-based guideline for the acquisition of brain volumes.

MATERIAL AND METHODS

This was a prospective multicenter study. Five centers recruited five cases each, acquiring two volumes per case, at different gestational age ranges. From the collected volumes, 10 operators performed an advanced neurosonography of each case. The evaluable anatomic structures were counted in each volume and expressed as a percentage. The results were compared with those obtained in a previous study where no recommendations had been made for the acquisition of the volumes.

RESULTS

Five hundred evaluations were included in the study. In the axial plane, 91.5% of the structures were satisfactorily evaluated, 81.8% in the coronal plane and 89.9% in the sagittal plane. These results were significantly better than those obtained in a previous study where the volumes had been acquired without any guidelines and the percentage of evaluable structures were 80% (P < .001), 67.1% (P < .001) and 55.1% (P < .001) in the axial, coronal and sagittal planes, respectively.

CONCLUSIONS

The application of an evidence-based guideline for the acquisition of brain volumes improves the quality of these by increasing the number of evaluable structures in the volume.

New Insights into the Anterior Complex

OBJECTIVE

To introduce visualization of the germinal matrix (GM), external angle of the frontal horn, and periventricular white matter while evaluating the anterior complex (AC) during basic ultrasound assessment of the fetal brain.

CASE PRESENTATIONS

This is a retrospective observational study of healthy women with singleton pregnancies, with no increased risk of fetal central nervous system anomalies, attending routine ultrasound screening at 20-32 weeks' gestation. Seventeen cases are presented in which an abnormal aspect of the GM or external angle of the frontal horn or periventricular white matter on AC evaluation has allowed a prenatal diagnosis of peri-intraventricular hemorrhage, subependymal cysts, connatal cysts, periventricular venous hemorrhagic infarction, and white matter injury.

CONCLUSION

An extended AC evaluation could significantly improve the -diagnosis of hemorrhagic/cystic/hypoxic-ischemic lesions during the performance of a basic ultrasound study of the fetal brain.

Mutations in TBX1 genocopy the 22q11.2 deletion and duplication syndromes: a new susceptibility factor for mental retardation

A screen for TBX1 gene mutations identified two mutations in patients with some features compatible with the 22q11.2-deletion syndrome but with no deletions. One is a de novo missense mutation and the other is a 5' untranslated region (5'UTR) C>T change that affects a nucleotide with a remarkable trans-species conservation. Computer modelling shows that the 5'UTR change is likely to affect the mRNA structure and in vitro translation experiments demonstrate that it produces a twofold increase in translation efficiency. Recently, duplications in the 22q11.2 region were reported in patients referred for fragile-X determination because of cognitive and behavioural problems. Because the 5'UTR nucleotide change may be a functional equivalent of a duplication of the TBX1 gene, we decided to screen 200 patients who had been referred for fragile-X determination and 400 healthy control individuals. As a result, we found the 5'UTR mutation to be present in three patients with mental retardation or behavioural problems and absent in control individuals of the same ethnic background. This observation suggests that it may be reasonable to screen for such mutation among patients with unspecific cognitive deficits and we provide an easy and quick way to do it with an amplification refractory mutation system (ARMS) approach. To our knowledge, this is the first human mutation showing that TBX1 is a candidate causing mental retardation associated with the 22q11.2 duplication syndrome.