New insights in cerebral findings associated with fetal myelomeningocele: a retrospective cohort study in a single tertiary centre.

OBJECTIVE: To investigate cerebral anomalies other than Chiari type 2 malformation in fetuses with myelomeningocele (MMC). DESIGN: A retrospective cohort study in a single tertiary centre. SETTING: A review of associated cerebral anomalies in cases with prenatal diagnosis of myelomeningocele. POPULATION: Seventy cases of fetal myelomeningocele. METHODS: Ultrasound and MRI images were blindly reviewed. Postnatal imaging and results of the postmortem results were also reviewed. The association between cerebral anomalies and the following ultrasound findings was measured: level of the defect, ventriculomegaly, microcephaly and fetal talipes. MAIN OUTCOME MEASURES: A microcephaly was observed in 32/70 cases (46%) and a ventriculomegaly was observed in 39/70 cases (56%). Other cerebral anomalies were diagnosed in 47/70 (67%). RESULTS: Other cerebral anomalies were represented by 42/70 cases with abnormal CC (60%), 8/70 cases with perinodular heterotopia (PNH; 11%), 2/70 cases with abnormal gyration (3%). MRI performed only in fetal surgery cases confirmed the ulltrasound findings in all cases and provided additional findings in two cases (PNH). Risk ratios of fetal cerebral anomalies associated with MMC did not reach significance for microcephaly, ventriculomegaly, talipes or the level of the defect There was an overall good correlation between pre- and postnatal findings with a Kappa value of 0.79 [95% CI 0.57-1] and 82% agreement. CONCLUSION: Fetal brain anomalies other than Chiari type 2 malformation are frequently observed in fetuses with myelomeningocele, predominantly represented by CC anomalies. Whether these associated cerebral anomalies have an impact on selecting cases eligible for fetal surgery needs further evaluation. TWEETABLE ABSTRACT: Fetal cerebral anomalies other than Chiari type 2 malformation, microcephaly, and ventriculomegaly may be associated with MMC in up to 67% of the cases.

Prevalence of COL4A1 and COL4A2 mutations in severe fetal multifocal hemorrhagic and/or ischemic cerebral lesions.

OBJECTIVE: To establish the prevalence of COL4A1 and COL4A2 gene mutations in fetuses presenting with a phenotype suggestive of cerebral injury. METHODS: This was a single-center retrospective analysis of all cases of fetal cerebral anomalies suggestive of COL4A1 or COL4A2 gene mutation over the period 2009-2018. Inclusion criteria were: (1) severe and/or multifocal hemorrhagic cerebral lesions; (2) multifocal ischemic-hemorrhagic cerebral lesions. These anomalies could be of different ages and associated with schizencephaly or porencephaly. Between fetuses with and those without a mutation, we compared gestational age at the time of diagnosis, parity and fetal gender. RESULTS: Among the 956 cases of cerebral anomaly diagnosed in our center during the 10-year study period, 18 fetuses were identified for inclusion. A pathogenic COL4A1 gene mutation was found in five of these cases, among which four were de-novo mutations. A variant of unknown significance was found in four fetuses: in the COL4A1 gene in one case and in the COL4A2 gene in three cases. No COL4A1 or COL4A2 mutation was found in the remaining nine fetuses. The median (interquartile range) gestational age at diagnosis was significantly lower in cases with a mutation (24 (22-26) weeks) than in cases without a mutation (32 (29.5-34.5) weeks) (P = 0.03). CONCLUSIONS: A phenotype suggestive of cerebral injury was found in 18 of the 956 (1.9%) cases in our population, in 28% of which there was an associated COL4A1 or COL4A2 mutation. COL4A1 and COL4A2 gene mutations should be sought systematically in cases of severe and/or multifocal hemorrhagic or ischemic-hemorrhagic cerebral lesions, with or without schizencephaly or porencephaly. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prognostic value of diffusion-weighted magnetic resonance imaging of brain in fetal growth restriction: results of prospective multicenter study.

OBJECTIVE: To measure prospectively apparent diffusion coefficient (ADC) values between 28 and 32 weeks of gestation in different cerebral territories of fetuses with estimated fetal weight (EFW) ≤ 5th centile, and analyze their association with adverse perinatal outcome. METHODS: This was a prospective study involving six tertiary-level perinatal centers. In the period 22 November 2016 to 11 September 2017, we included singleton, small-for-gestational-age (SGA) fetuses with EFW ≤ 5th percentile, between 28 and 32 weeks of gestation, regardless of the umbilical artery Doppler and maternal uterine artery Doppler findings. A fetal magnetic resonance imaging (MRI) examination with diffusion-weighted sequences (DWI) was performed within 14 days following inclusion and before 32 weeks. ADC values were calculated in the frontal and occipital white matter, basal ganglia and cerebellar hemispheres. An ultrasound examination was performed within 1 week prior to the MRI examination. The primary outcome was a composite measure of adverse perinatal outcome, defined as any of the following: perinatal death; admission to neonatal intensive care unit with mechanical ventilation > 48 h; necrotizing enterocolitis; Grade III-IV intraventricular hemorrhage; periventricular leukomalacia. A univariate comparison of median ADC values in all cerebral territories between fetuses with and those without adverse perinatal outcome was performed. The association between ADC values and adverse perinatal outcome was then analyzed using multilevel logistic regression models to adjust for other common prognostic factors for growth-restricted fetuses. RESULTS: MRI was performed in 64 patients, of whom five were excluded owing to fetal movement artifacts on DWI and two were excluded for termination of pregnancy with no link to fetal growth restriction (FGR). One intrauterine death occurred secondary to severe FGR. Among the 56 liveborn neonates, delivered at a mean ± SD gestational age of 33.6 ± 3.0 weeks, with a mean birth weight of 1441 ± 566 g, four neonatal deaths occurred. In addition, two neonates required prolonged mechanical ventilation, one of whom also developed necrotizing enterocolitis. Overall, therefore, seven out of 57 (12.3%) cases had an adverse perinatal outcome (95% CI, 3.8-20.8%). The ADC values in the frontal region were significantly lower in the group with adverse perinatal outcome vs those in the group with favorable outcome (mean values of both hemispheres, 1.68 vs 1.78 × 10-3 mm2 /s; P = 0.04). No significant difference in ADC values was observed between the two groups in any other cerebral territory. A cut-off value of 1.70 × 10-3 mm2 /s was associated with a sensitivity of 57% (95% CI, 18-90%), a specificity of 78% (95% CI, 63-88%), a positive predictive value of 27% (95% CI, 8-55%) and a negative predictive value of 93% (95% CI, 80-98%) for the prediction of adverse perinatal outcome. A mean frontal ADC value < 1.70 × 10-3 mm2 /s was not associated significantly with an increased risk of adverse perinatal outcome, either in the univariate analysis (P = 0.07), or when adjusting for gestational age at MRI and fetal sex (odds ratio (OR), 6.06 (95% CI, 0.9-37.1), P = 0.051) or for umbilical artery Doppler (OR, 6.08 (95% CI, 0.89-41.44)). CONCLUSION: This first prospective, multicenter, cohort study using DWI in the setting of SGA found lower ADC values in the frontal white-matter territory in fetuses with, compared with those without, adverse perinatal outcome. To determine the prognostic value of these changes, further standardized evaluation of the neurodevelopment of children born with growth restriction is required. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Towards ontology-based decision support systems for complex ultrasound diagnosis in obstetrics and gynecology.

INTRODUCTION: We have developed a new knowledge base intelligent system for obstetrics and gynecology ultrasound imaging, based on an ontology and a reference image collection. This study evaluates the new system to support accurate annotations of ultrasound images. We have used the early ultrasound diagnosis of ectopic pregnancies as a model clinical issue. MATERIAL AND METHODS: The ectopic pregnancy ontology was derived from medical texts (4260 ultrasound reports of ectopic pregnancy from a specialist center in the UK and 2795 Pubmed abstracts indexed with the MeSH term "Pregnancy, Ectopic") and the reference image collection was built on a selection from 106 publications. We conducted a retrospective analysis of the signs in 35 scans of ectopic pregnancy by six observers using the new system. RESULTS: The resulting ectopic pregnancy ontology consisted of 1395 terms, and 80 images were collected for the reference collection. The observers used the knowledge base intelligent system to provide a total of 1486 sign annotations. The precision, recall and F-measure for the annotations were 0.83, 0.62 and 0.71, respectively. The global proportion of agreement was 40.35% 95% CI [38.64-42.05]. DISCUSSION: The ontology-based intelligent system provides accurate annotations of ultrasound images and suggests that it may benefit non-expert operators. The precision rate is appropriate for accurate input of a computer-based clinical decision support and could be used to support medical imaging diagnosis of complex conditions in obstetrics and gynecology.

[Intrauterine blood transfusion: Status report of 4years of practice in France (2011-2014)]. / Transfusions fœtales érythrocytaires : état des lieux sur 4 ans en France (2011­2014).

OBJECTIVES: The aim of our study was to evaluate in utero blood transfusion's (IUT) performed in France, among the French prenatal diagnosis centers in order to study the etiology of severe anemia requiring IUT. METHODS: We conducted a national retrospective descriptive study between 2011 and 2014. The data were collected using a survey sent by email to all French prenatal diagnosis centers. RESULTS: Among the 49 centers, 18 (38 %) had performed at least one IUT during the study period. The geographical repartition of these centers was appropriate for the "Aquitaine Pyrénées" region. Five centers performed 68 % of the national activity and one center performed 40 % the national activity. Each year, a mean of 204 IUTs were performed in 113 pregnancies. The principal etiology of severe fetal anemia requiring IUT was hemolytic disease of the fetus (69 % of the etiologies) with anti-RhD being the most prevalent antibody. The second etiology was represented by parvovirus B19 infection (17 % of IUTs). CONCLUSION: The French IUT activity was stable in numbers and indications during the study period. A national register could be set up in order to better evaluate prospectively the number of pregnancies concerned by IUT and to study the prevalence of hemolytic disease of the fetus due to anti-RhD antibodies.

[How to assess the neutral position of the fetus for the crown-rump length measurement at the nuchal translucency scan]. / Comment évaluer la flexion de l'embryon lors de la mesure de la longueur cranio-caudale.

OBJECTIVES: The objective of this study was to establish a simple and reproducible method for the assessment of the fetal head position when measuring crown-rump length (CRL) at the nuchal translucency scan. METHODS: Two observers conducted a retrospective analysis of a consecutive series of 570 images of CRL collected by the French College of Fetal Echography (CFEF) national practice assessment program for the first-trimester scan. The images were deemed hyper-flexed if no fluid was visible between the chin and the chest of the fetus. The images were deemed hyper-extended if the angle between the palate and the CRL line was 90° or more. The images were deemed neutral if no hyper-extension nor hyper-flexion was observed. RESULTS: The proportion of agreement for a non-neutral position of the fetal head was 91.3% (kappa=0.80, 95% CI [0.75 to 0.86]). Images with a non-neutral position corresponded to poor CRL quality images according to the CFEF score (relative risk=4.2, 95% CI [2.9 to 6.1] for one observer and 4.9, 95% CI [3.3 to 7.2] for the other observer). Proportions of agreement for the hyper-flexion and for the hyper-extension were 94.6% (kappa=0.80, 95% CI [0.72 to 0.87]) and 96.8% (kappa=0.81, 95% CI [0.72 to 0.90]), respectively. No additional lines were drawn on the ultrasound images during the evaluation process. CONCLUSIONS: The proposed method for evaluating the extent to which the fetal head has a non-neutral position at measurement of the CRL appears both simple and reproducible.

[Preliminary results from the French study on prenatal repair for fetal myelomeningoceles (the PRIUM study)]. / Résultats préliminaires de l'étude PRIUM : programme de réparation in utero des myéloméningocèles.

OBJECTIVES: To present the preliminary results of the PRIUM study, a French pilot study of prenatal repair for myelomeningoceles (MMC). MATERIAL AND METHODS: The fetal surgery for MMC is offered in cases of patients that did not opt for termination of pregnancy. RESULTS: Thirty-six patients were referred in an 18-month period. Eight patients were not eligible for prenatal repair. Another type of dysraphism was made in 6 cases (one spina-lipoma, 5 cases of limited dorsal myeloschisis). Twenty-two patients were eligible to fetal surgery. A prenatal repair was performed in three cases (14%). Four patients opted for a conventional postnatal treatment. Fifteen patients opted for termination of the pregnancy. CONCLUSION: The establishment of a prenatal repair of MMC protocol in France was justified. The experience of the first 18months of this study however suggests that only a limited number of couples will choose this procedure after specialized counseling in a reference center.

[A simple self-assessment tool for the first-trimester ultrasound images]. / Une auto-évaluation simplifiée des images échographiques du premier trimestre.

OBJECTIVES: The objective of this study was to establish a minimum subset of simple criteria for the self-assessment of the quality of first-trimester ultrasound images of nuchal translucency (NT) and crown-rump length (CRL). METHODS: We designed 162 simplified image-scoring methods (ISM) based on 1, 2, 3 or 4 binary criteria derived from the 8 criteria of the original image scoring method of the French College of Fetal Ultrasound (CFEF). These ISM were assessed on 68,250 consecutive scans of the French national audit conducted by the CFEF on NT and CRL images. The ISM associated with the best precision to identify excellent/reasonable quality scans were selected. RESULTS: Simplified ISM based on 1, 2, 3 and 4 criteria showed maximum positive predictive values of 95.3% (95.11-95.50) 98.0% (97.87-98.14), 99.3% (99.17-99.35) and 99.7% (99.68-99.79), respectively, to identify excellent/reasonable quality scans. The proportion of excellent/reasonable scans was 2.8 to 16.7% when three criteria among the 8 were insufficient, and 0.17 to 3.95% when four criteria were insufficient. CONCLUSIONS: The best performing ISM was based on the following four quality criteria: (i) sagittal plane of the NT, (ii) calipers placement for measuring the NT, (iii) image magnification of NT images and (iv) CRL measurement. This score might be the most relevant in clinical practice in the first-trimester screening.

[Fetal abdominal cysts at the first trimester scan]. / Images kystiques abdominales fœtales du premier trimestre.

OBJECTIVES: Abdominal cysts are seldom detected at the first trimester scan. The aim of this study is to ascertain their outcome, which is currently not established. METHODS: The French College of Fetal Ultrasound conducted a prospective observational study of 24months, collecting all cases of abdominal cysts discovered during the first trimester ultrasound. Cases of megacystis were excluded from the study. Ultrasound images, prenatal diagnosis expert reports and pregnancy outcomes were collected by sonographers after patient consent. RESULTS: Ten cases of abdominal cysts were collected. The cysts had a mean diameter of 15mm. They were anechoic in 5 cases, hyperechoic in 2 cases and mixed in 3 cases. In 6 of 10 cases, complete resolution was observed at 18WG with a good post-natal outcome; the five cases with anechoic images were associated with normal pediatric examination at birth and in the case of the resolved hyperechoic image, an isolated imperforate anus was observed. In the four cases of hyperechoic or mixed images that had not resolved, the outcome was poor with four termination of pregnancies, including two cases of cloacal dysgenesis. CONCLUSIONS: Abdominal cysts are rare at the first trimester scan. They resolve in two thirds of cases and are then associated with good outcome. When they do not resolve or when they are not strictly anechoic, they require a referral ultrasound examination at 18 and 22WG.

Determination of optimal timing of serial in-utero transfusions in red-cell alloimmunization.

OBJECTIVES: To assess the performance of middle cerebral artery peak systolic velocity (MCA-PSV) and of the expected daily decrease in fetal hemoglobin in determining the timing of serial in-utero transfusions (IUT) in red-cell alloimmunization. METHODS: This was a retrospective study of a continuous series of suspected anemic fetuses undergoing IUT between June 2003 and December 2012. Doppler measurement of MCA-PSV and pre- and post-transfusion hemoglobin levels were recorded at the time of the first, second and third IUT. Receiver-operating characteristics (ROC) curves and negative and positive predictive values of MCA-PSV in the prediction of severe fetal anemia were calculated. The daily decrease of fetal hemoglobin (Hb) between IUTs was calculated. Regression analysis was used to assess the correlation between pretransfusion fetal hemoglobin and MCA-PSV, and between observed and expected (by projection of daily decreases) pretransfusion fetal hemoglobin levels. RESULTS: One hundred and eleven fetuses required an IUT, of which 96 and 67 received a second and third IUT, respectively. The area under the ROC curve for MCA-PSV in the prediction of severe fetal anemia was not different for each rank of transfusion. The positive predictive value of MCA-PSV decreased from 75.3% at the first IUT, to 46.7% and 48.8% at the second and third IUTs, respectively, while the negative predictive value for a 1.5-MoM threshold remained high (88.9% at the second and 91.7% at the third IUT). The mean daily decrease in hemoglobin following each transfusion was 0.45, 0.35 and 0.32 g/dL, respectively. There was a persistent linear correlation between fetal hemoglobin and MCA-PSV and between observed and expected fetal hemoglobin levels. CONCLUSIONS: Both MCA-PSV and projection of daily decrease in hemoglobin are reliable means of diagnosing fetal anemia following previous IUTs. The high negative predictive value of MCA-PSV could allow subsequent IUTs to be postponed in selected cases.

Limits of the surgically induced model of myelomeningocele in the fetal sheep.

PURPOSE: The prevention of Chiari type II malformation (CM) is commonly used as a primary outcome for the evaluation of techniques of fetal myelomeningocele (MMC) surgery in the fetal lamb. The aim of our study was to investigate the frequency of the associated CM in the MMC fetal sheep model and to investigate the contribution of prenatal ultrasound evaluation of CM at the time of prenatal repair. METHODS: A MMC-like lesion was surgically created at 75 days of gestation in 21 fetuses performing a L1-L5 laminectomy followed by an excision of the exposed dura and a midline myelotomy. At a 90-day gestation, among the 19 alived fetuses, a conventional repair of the MMC-like lesion was performed in seven, four of whom underwent cerebral ultrasound (US) examination before the repair. Twelve fetuses remained untreated (control group). All fetuses underwent post-mortem examination (PM) at 138 days. RESULTS: At a 90-day gestation, CM was demonstrated by US examination in all four evaluated fetuses. At birth, CM was found in 3/6 control whether CM was absent in all alived fetuses in the prenatal repair group (n = 4). CONCLUSIONS: Creation of a MMC-like lesion with an additional myelotomy does not always lead to hindbrain herniation. Our study suggests that CM should be assessed by ultrasound examination at the time of the prenatal repair to demonstrate the effectiveness of new techniques for the prenatal repair of MMC.

Screening for fetal spina bifida at the 11-13-week scan using three anatomical features of the posterior brain.

OBJECTIVE: To evaluate the contribution of examination of specific anatomical features of the fetal posterior brain on mid-sagittal first-trimester ultrasound examination to the early detection of open spina bifida. METHODS: Four independent observers reviewed a series of 260 mid-sagittal first-trimester ultrasound images from 52 cases of open spina bifida and 208 normal fetuses. The following analysis was performed by each reviewer for each image: Herman score calculation, intracranial translucency score (CFEF-IT) calculation and determination of presence or absence of three anatomical criteria: intracranial translucency (IT), caudal displacement of the brainstem and cisterna magna. The sensitivity and the false-positive rate for spina bifida detection were calculated for each of the latter three criteria. A secondary analysis was performed on the subset of images achieving a Herman score ≥ 7. RESULTS: The highest detection rate for spina bifida was achieved by non-visualization of the cisterna magna, with associated sensitivity of 50-73% and 39-76%, respectively, for all images and for the subset of images achieving a Herman score ≥ 7. Posterior shift of the brainstem achieved the highest detection rate (86%), but for a single reviewer only. The level of variation in performance between observers was also greatest for this sign. Absence of IT was associated with a lower detection rate for all observers. Overall, an abnormal posterior brain presenting at least one of these three criteria was associated with a detection rate ranging from 50 to 90%. CONCLUSION: In the detection of spina bifida, non-visualization of the cisterna magna achieved the best screening performance. Both non-visualization of the IT and posterior shift of the brainstem were associated with acceptable but lower detection rates. A prospective evaluation of changes in the posterior brain is needed to allow assessment of the most pertinent criteria for first-trimester screening for spina bifida.