Fetal Central Nervous System Abnormalities Research Articles

Comparison of prenatal central nervous system abnormalities with postmortem findings infetuses following termination of pregnancy andclinical utility of postmortem examination.

In this study, we aimed to compare prenatal ultrasound (USG) and postmortem examination findings of central nervous system (CNS) abnormalities in fetuses following termination of pregnancy (TOP). A total of 190 fetuses with USG-confirmed fetal CNS abnormalities of terminated pregnancies between January 2001 and January 2017 were retrospectively analyzed and USG and postmortem examination findings were compared. The most frequent CNS abnormalities were acrania/anencephaly (n=45, 24%), spina bifida (n=43, 23%), and ventriculomegaly (n=35, 18%). In 144 of the 190 (76%) cases, there was total agreement between USG and postmortem examination diagnosis. Postmortem examination provided minor findings which did not change the major clinical diagnosis in two (1%) cases with spina bifida and ventriculomegaly. In six (3%) cases, the diagnosis changed after postmortem examination. In 25 of the 190 (13%) cases with multiple abnormalities as evidenced by USG, CNS abnormality was unable to be confirmed at postmortem examination. Our study results show an overall high agreement (76%) between USG and postmortem examination findings for CNS malformations. Due to autolysis and fluid structure, USG-confirmed CNS diagnosis cannot be always confirmed by postmortem examination. This potential discrepancy should be explained to patients before considering TOP. Postmortem examination is the gold standard to confirm prenatal diagnosis.

Clinical Utility and the Yield of Single Nucleotide Polymorphism Array in Prenatal Diagnosis of Fetal Central Nervous System Abnormalities.

Applying single nucleotide polymorphism (SNP) array to identify the etiology of fetal central nervous system (CNS) abnormality, and exploring its association with chromosomal abnormalities, copy number variations, and obstetrical outcome. 535 fetuses with CNS abnormalities were analyzed using karyotype analysis and SNP array. Among the 535 fetuses with CNS abnormalities, chromosomal abnormalities were detected in 36 (6.7%) of the fetuses, which were consistent with karyotype analysis. Further, additional 41 fetuses with abnormal copy number variations (CNVs) were detected using SNP array (the detection rate of additional abnormal CNVs was 7.7%). The rate of chromosomal abnormalities, but not that of pathogenic CNVs in CNS abnormalities with other ultrasound abnormalities was significantly higher than that in isolated CNS abnormalities. The rates of chromosomal abnormalities and pathogenic CNVs in fetuses with spine malformation (50%), encephalocele (50%), subependymal cyst (20%), and microcephaly (16.7%) were higher than those with other isolated CNS abnormalities. The pregnancies for 36 cases with chromosomal abnormalities, 18 cases with pathogenic CNVs, and three cases with VUS CNVs were terminated. SNP array should be used in the prenatal diagnosis of fetuses with CNS abnormalities, which can enable better prenatal assessment and genetic counseling, and affect obstetrical outcomes.

Detecting Fetal Central Nervous System Anomalies Using Magnetic Resonance Imaging and Ultrasound

Background:Most fetal abnormalities can be detected on ultrasound, the evaluation of fetal CNS abnormalities can be limited by various factors, including obesity, polyhydramnios, multiple pregnancies, and increased cranial ossification during the third trimester.Objective:This study aimed to evaluate the ability to detect fetal central nervous system (CNS) anomalies using in utero magnetic resonance imaging (iuMRI) and ultrasound (US) techniques.Methods:This prospective study was approved by the institutional review board (Ref: 2968/QĐ-ĐHYHN dated 11 July 2019), and the requirement to obtain the informed consent of patients was waived. This study included 66 fetuses with diagnosed or suspected CNS abnormalities based on the results of a prenatal screening US performed at the antenatal diagnosis center of the Central Obstetrics and Gynecology Hospital. All pregnant women with a suspected diagnosis of abnormal fetal CNS on US underwent 1.5-Tesla iuMRI within 14 days of the US at Hanoi Medical University Hospital between June 2019 and June 2020. Cohen’s kappa coefficient (κ) was used to determine the agreement between US and iuMRI findings.Results:A total of 66 pregnant women were examined, including 66 fetuses, for which 79 abnormalities were detected by US and 98 abnormalities were detected by iuMRI. The average gestational age was 29 weeks and 6 days. The comparison of iuMRI and US findings revealed similar diagnoses for 71 abnormalities (67%) and different diagnoses for 35 abnormalities (33%). The level of agreement between US and iuMRI was almost perfect for ventriculomegaly and cystic lesions, with κ values 0.87 and 0.84, respectively. The level of agreement between US and iuMRI was the weakest for hemorrhage, with a κ value 0 (no agreement), and cortical abnormalities, with a κ value of 0.46 (weak agreement).Conclusion:The level of agreement between US and iuMRI diagnoses was almost perfect for the detection of ventriculomegaly and was weakest for the detection of hemorrhage and cortical abnormalities, which were abnormalities detected by iuMRI but not by ultrasound.

Trizomi 13 ve 18 ile ilişkili prenatal sonografik bulgular; tek bir merkezde prenatal tanı konmuş olguların sunumu

Purpose: In this retrospective study, we aimed to evaluate the prenatal sonographic findings of the fetuses with trisomy 13 and 18. Materials and Methods: The sonographic findings of fetuses which were prenatally diagnosed as trisomy 13 and 18 were retrospectively reviewed in two years’ period at a single tertiary perinatal center. The most common findings for each aneuploidy were described. Results: Total 13 cases were diagnosed as trisomy 13 or 18 during two years’ period of which three cases were trisomy 13 and 10 cases were trisomy 18. Major sonographic abnormality associated with trisomy 13 was holoprosencephaly while cardiac abnormalities were the leading finding for trisomy 18. Conclusion: Trisomy 13 and 18 have major prenatal sonographic findings that may be detected with a targeted sonographic examination. Fetal cardiac and central nervous system abnormalities are the primary major findings associated with trisomy 13 and 18.

Abnormalities of the Fetal Central Nervous System: Prenatal US Diagnosis with Postnatal Correlation.

Fetal central nervous system (CNS) abnormalities are second only to cardiac malformations in their frequency of occurrence. Early and accurate diagnosis at prenatal US is therefore essential, allowing improved prenatal counseling and facilitating appropriate referral. Thorough knowledge of normal intracranial anatomy and adoption of a logical sonographic approach can improve depiction of abnormal findings, leading to a more accurate differential diagnosis earlier in pregnancy. Four standard recommended views-transventricular, falx, cavum, and posterior fossa or transcerebellar views-provide an overview of fetal intracranial anatomy during the second trimester anatomy scan. Essential elements surveyed in the head and neck include the lateral cerebral ventricles, choroid plexus, midline falx, cavum septi pellucidi, cerebellum, cisterna magna, upper lip, and nuchal fold. CNS abnormalities can be organized into six main categories at prenatal US. Developmental anomalies include neural tube defects and neuronal migration disorders. Posterior fossa disorders include Dandy-Walker malformation variants and Chiari II malformation. Ventricular anomalies include aqueductal stenosis. Midline disorders include those on the spectrum of holoprosencephaly, agenesis of the corpus callosum, and septo-optic dysplasia. Vascular anomalies include vein of Galen malformations. Miscellaneous disorders include hydranencephaly, porencephaly, tumors, and intracranial hemorrhage. Correlation with postnatal MRI is helpful for confirmation and clarification of suspected diagnoses after birth. The authors discuss a standard US imaging approach to the fetal CNS and review cases in all categories of CNS malformations, providing postnatal MRI correlation when available.©RSNA, 2020.

The comparative study of antenatal magnetic resonance imaging and ultrasound in the evaluation of fetal central nervous system abnormalities

Background: The role of fetal magnetic resonance imaging (MRI) was studied in antenatal anomalies detected by ultrasound. Materials and Methods: The study was conducted in the Department of Radiodiagnosis and Imaging, Government Medical College, Srinagar, over a period of 12 months including all pregnant women with suspected fetal anomalies on ultrasonography (US). Results: In 9/23 cases (39.1%), the US findings and MRI findings were similar. MRI changed the diagnosis in 11/23 cases (47.8%). MRI provided additional information than US in 2/23 cases (8.69%), and there was 1/23 (4.3%) cases in which US provided additional information to that provided by MRI in terms of intrauterine growth restriction. Conclusions: US and MRI are complementary to each other in reaching a diagnosis in the fetal central nervous system abnormalities, and MRI is a major problem-solving modality where the US findings are inconclusive. The major role for fetal MRI was found in confirmation of inconclusive sonographic findings and the evaluation of sonographically occult diagnoses.

Zika virus infection: A correlation between prenatal ultrasonographic and postmortem neuropathologic changes

This study presents a correlation between prenatal ultrasonographic images and neuropathologic findings of postmortem tissue samples from five confirmed cases of perinatal Zika virus (ZIKV) infection belonging to the cohort of the ZEN Initiative in Bucaramanga, Colombia. Deaths occurred between June 2016 and March 2017. Mothers consulted with ZIKV infection clinical manifestations or fetal central nervous system (CNS) abnormalities or both. A detailed ultrasound scan and neurosonographic protocol was performed by maternal fetal specialists. Perinatal autopsies were performed following the Colombian National Health Institute's ZIKV protocol. The autopsies were from two fetal deaths, and three early neonatal deaths. Gestational age was between 262/7 and 382/7 weeks. Two cases were classified as mild microcephaly. Few findings by ultrasound and pathology were found in case 1 because it was a late infection; the other cases presented findings corresponding to congenital Zika syndrome: craniofacial malformations, cerebellar hypoplasia, anomalies of the corpus callosum and ventriculomegaly, all confirmed in autopsy specimens. By ultrasonography, hyperechogenicities were seen in several brain structures, which correspond to cortical and periventricular calcifications, subependymal glial reactivity and perivascular rings. The ultrasound and pathological findings show a wide spectrum of CNS anomalies that confirm the neurotropic effect of the ZIKV, recognizing the neuroimaging findings of this disease (unilateral ventriculomegaly, alterations in the corpus callosum and cerebellum, and calcifications) are highly suggestive of ZIKV infection.

OP09.01: Is MRI better than neurosonogram for fetal central nervous system abnormalities?

OP09.01: Is MRI better than neurosonogram for fetal central nervous system abnormalities?

Obstetric management, tests, and technologies that impact childhood development.

Childhood brain development begins before birth, and obstetric management, tests, and technologies designed to diagnose and treat fetal conditions can have an impact on development. Preconception counseling for maternal diabetes and hypertension affect the risk of fetal congenital anomalies and growth restriction. Patients with risk factors for pre-existing maternal diabetes are offered early diabetic screening because earlier diagnosis and treatment can decrease the risk of fetal and neonatal complications. Screening for chromosomal abnormalities in the first or second trimester is offered to all females regardless of age. Cell-free fetal DNA screening can be used to test for fetal genetic abnormalities as early as 9weeks of gestation with results available in 10days. Ultrasound performed around 20weeks' gestation can identify the 3% of fetuses that have a major congenital malformation. Fetal magnetic resonance imaging can be used to better assess fetal central nervous system abnormalities when neurosonography is inconclusive. Doppler ultrasound can be used to assess blood flow in the umbilical artery and fetal middle cerebral artery to aid in the management of the growth-restricted fetus. In summary, diagnosis and treatment of maternal and fetal conditions from the preconception period throughout pregnancy are important for optimizing fetal health and provide the best opportunity for optimal child development. WHAT THIS PAPER ADDS: Cell-free fetal DNA screening can identify fetal genetic abnormalities as early as 9weeks' gestation. Ultrasound performed around 20weeks' gestation can detect major fetal congenital malformations. Fetal magnetic resonance imaging can aid neurosonography in the assessment of fetal central nervous system abnormalities. Doppler ultrasound to assess fetal blood flow is used to successfully manage the growth-restricted fetus.

EP09.02: Comparative study of ultrasound and magnetic resonance imaging in the diagnosis of fetal central nervous system abnormalities

EP09.02: Comparative study of ultrasound and magnetic resonance imaging in the diagnosis of fetal central nervous system abnormalities

Watch out for congenital Zika syndrome in non-endemic regions.

Zika virus (ZIKV), first discovered in 1947, is the most recent member of the TORCH family. It usually causes an asymptomatic or mildly symptomatic disease in infected adults but can lead to severe brain abnormalities in fetuses who are infected in utero by vertical transmission of the virus through the placenta. The constellation of these fetal/neonatal abnormalities is named as congenital Zika syndrome (CZS). Although horizontal transmission of ZIKV is largely dependent on the presence of the vector (i.e. Aedes mosquitoes), women residing in non-endemic areas are still at risk of acquiring the infection once they travel to an endemic region or have unprotected sexual contact with an infected male. Therefore, it is important for physicians practicing in non-endemic regions to be familiar with the clinical and neuroimaging manifestations of CZS and to consider this diagnosis as a potential etiology for congenital microcephaly and other fetal central nervous system abnormalities.

MRI features of the placenta in fetuses with and without CNS abnormalities

To investigate if magnetic resonance imaging (MRI) features of the placenta are different in fetuses with and without central nervous system (CNS) abnormalities. Institutional research ethics board approval was obtained. Fetal MRI of 97 singleton pregnancies were analysed retrospectively (19-25 weeks gestation), 65 with CNS morphological abnormalities and 32 controls. Placental T2 signal intensity, placental and fetal volumes, placental-to-fetal volume ratio, and placental apparent diffusion coefficient (ADC) values were assessed. Measurements were compared with the presence or absence of CNS fetal abnormalities using the Mann-Whitney test. Separate slopes models and intercept models were used to check for significant differences in the slopes and intercepts, respectively, among the groups. Placental ADC values were significantly lower in placentas of fetuses with CNS abnormalities compared to controls (p=0.04). Placental T2 signal intensity, fetal and placental volumes did not differ between the two groups. The rate of increase in fetal-to-placental volume ratio with gestational age (GA) was greater among the controls. The presence of fetal CNS abnormalities is associated with reduced ADC values of the placenta. Moreover, placentas of fetuses with CNS abnormalities show a less rapid increase in fetal to placental volume ratio with GA. Therefore, ADC mapping, as well as different growth kinetics of the placenta relative to the fetus, may potentially serve as early markers of pathological neurodevelopment.

Evaluating the incidence and likelihood ratios for chromosomal abnormalities in fetuses with common central nervous system malformations

To determine the incidence and likelihood ratios for chromosomal abnormalities in fetuses with common central nervous system malformations on ultrasound. A database derived retrospective cohort study of all patients referred for ultrasound and genetic evaluation from 1990-2006. Fetal karyotypes were delineated by prenatal diagnosis or postnatal examination. The incidence and likelihood ratios were calculated for the association of each central nervous system abnormality with trisomy 13, 18, and 21. Of 62,111 women included, 587 (0.9%) had major fetal central nervous system abnormalities. The only central nervous system anomalies associated with trisomy 21 were ventriculomegaly and choroid plexus cysts. When isolated, only spina bifida, holoprosencephaly, and agenesis of the corpus callosum were significantly associated with trisomy 13, anencephaly with trisomy 18, and ventriculomegaly with trisomy 21. Likelihood ratios positive range from 2-20 depending on the central nervous system malformation and aneuploidy type. Central nervous system malformations detected on ultrasound are strongly associated with and predictive of chromosomal abnormalities, especially trisomy 13 and 18.

Sonographic examination of the fetal central nervous system: guidelines for performing the ‘basic examination’ and the ‘fetal neurosonogram’

Sonographic examination of the fetal central nervous system: guidelines for performing the ‘basic examination’ and the ‘fetal neurosonogram’

A review of the current use of magnetic resonance imaging in pregnancy and safety implications for the fetus

This paper presents an overview of the application of and risks of exposure to Magnetic Resonance Imaging (MRI) in pregnancy. It reviews the risks to the fetus by considering the hazards in terms of the three main components of an MRI system. These are the static magnetic field, the time-varying magnetic gradient fields and the pulsed radio frequency fields. The hazards discussed are biological effects, miscarriage, heating effects and acoustic noise exposure. This paper also presents a survey of MRI sites within the United Kingdom to ascertain the extent of MRI usage in pregnancy. To validate the situation of MRI in pregnancy a survey was sent to 352 MR units throughout the United Kingdom. The questions were grouped to assess (a) maternal MRI diagnosis (b) fetal MRI and (c) work practices for pregnant MRI staff. The results showed that 91% of sites were imaging pregnant women in need of diagnosis in the second and third trimester. This paper highlights that MRI can add information for fetal central nervous system abnormalities identified by ultrasound screening, however within the UK direct fetal imaging was only performed in 8% of sites. This paper indicates the need for research to be undertaken for specific MRI clinical conditions. It also advises that risk assessment for pregnant staff working in MRI is performed, and that there is a clear need for further research into the effects of MRI in pregnancy as there is a need for clear authoritive advice.

Fast MR imaging of fetal central nervous system abnormalities.

To evaluate with respect to gestational age (GA) the effect of magnetic resonance (MR) imaging on changes in diagnosis, patient counseling, and case management regarding fetuses suspected of having central nervous system (CNS) anomalies. The authors compared images from 242 ultrasonographic (US) studies and 242 MR imaging studies of the CNS in 214 fetuses. Reference standards of postnatal physical examination, imaging, surgical, and autopsy findings were available in 171 (79.9%) fetuses. Referring physicians were surveyed on how MR imaging findings changed patient counseling or case management. Outcomes were compared with respect to GA. Statistical tests used were the Fisher exact test, Student t test, and analysis of variance. Confirmatory US findings were normal in 69 fetuses. MR imaging findings changed diagnosis in 46 of 145 (31.7%) fetuses with abnormal US findings. The mean GA of 72 of 145 fetuses with changes in maternal counseling (25.9 weeks) was significantly greater than that in 73 of 145 fetuses without changes in maternal counseling (22.6 weeks, P <.01). The mean GA of the 46 fetuses with changes in diagnosis (26.3 weeks) was significantly greater than that of the 99 fetuses with no major change in diagnosis (23.3 weeks, P <.01). There were 27 of 145 changes in case management, with no significant difference in mean GA of fetuses with and those without changes in case management. In fetuses with abnormal US findings, MR images were used to decide to terminate the pregnancy (n = 13; mean GA, 20.1 weeks), continue the pregnancy (n = 4; mean GA, 19.2 weeks), direct the mode and/or location of delivery (n = 5; mean GA, 30.5 weeks), and direct perinatal care (n = 5; mean GA, 30.2 weeks). When a CNS anomaly is detected or suspected at US, MR imaging may demonstrate additional findings that can alter diagnosis and case management. Changes in management are GA dependent.

Ultrasound versus magnetic resonance imaging (MRI) in fetal central nervous system abnormalities

Ultrasound versus magnetic resonance imaging (MRI) in fetal central nervous system abnormalities

Three-dimensional ultrasound in fetal central nervous system abnormalities

Three-dimensional ultrasound in fetal central nervous system abnormalities

Second-opinion magnetic resonance imaging for suspected fetal central nervous system abnormalities

Objective: The purpose of this study was to evaluate the relationship of magnetic resonance imaging and gestational age in the setting of fetuses with suspected abnormalities of the central nervous system that were detected by ultrasound scanning. Study design: Multiplanar magnetic resonance studies were performed in fetuses with suspected central nervous system abnormalities on ultrasound scanning. Magnetic resonance imaging was evaluated for its ability to provide additional information, change the diagnosis, or impact obstetric treatment. Patients were grouped by gestational age at the time of magnetic resonance imaging. Results: Magnetic resonance imaging provided additional information in 46 of 72 pregnancies (64%), changed the diagnosis in 20 of 72 pregnancies (28%), and potentially altered the timing or mode of delivery in 8 of 72 pregnancies (11%). Additional information increased with increasing gestational age groups (P = .03). Conclusion: Magnetic resonance imaging provided additional information in two thirds of the fetuses with central nervous system abnormalities, which was significantly increased with increasing gestation. Antenatal treatment was influenced by magnetic resonance imaging in 11% of the cases. (Am J Obstet Gynecol 2003;188:492-6.)

MR imaging of fetal central nervous system abnormalities

Ultrasound is the screening modality of choice for fetal imaging. However, when additional information regarding fetal anatomy or pathology is needed, fast MR imaging is increasingly being used as a correlative imaging modality. Performances of high quality sonographic and MR examinations as well as interpretation by individuals familiar with prenatal diagnosis are important factors for optimal parental counseling. MR imaging frequently adds additional information regarding fetal central nervous system anomalies beyond that available with ultrasound. This information commonly changes patient counseling, and at times patient management.