Evaluation of screening performance of first-trimester competing-risks prediction model for small-for-gestational age in Asian population

OBJECTIVE

To examine the external validity of the Fetal Medicine Foundation (FMF) competing-risks model for the prediction of small-for-gestational age (SGA) at 11-14 weeks' gestation in an Asian population.

METHODS

This was a secondary analysis of a multicenter prospective cohort study in 10 120 women with a singleton pregnancy undergoing routine assessment at 11-14 weeks' gestation. We applied the FMF competing-risks model for the first-trimester prediction of SGA, combining maternal characteristics and medical history with measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF) concentration. We calculated risks for different cut-offs of birth-weight percentile (< 10th , < 5th or < 3rd percentile) and gestational age at delivery (< 37 weeks (preterm SGA) or SGA at any gestational age). Predictive performance was examined in terms of discrimination and calibration.

RESULTS

The predictive performance of the competing-risks model for SGA was similar to that reported in the original FMF study. Specifically, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA with birth weight < 10th percentile (SGA < 10th ) and preterm SGA with birth weight < 5th percentile (SGA < 5th ), with areas under the receiver-operating-characteristics curve (AUCs) of 0.765 (95% CI, 0.720-0.809) and 0.789 (95% CI, 0.736-0.841), respectively. Combining maternal factors with MAP and PlGF yielded the best model for predicting preterm SGA with birth weight < 3rd percentile (SGA < 3rd ) (AUC, 0.797 (95% CI, 0.744-0.850)). After excluding cases with pre-eclampsia, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA < 10th and preterm SGA < 5th , with AUCs of 0.743 (95% CI, 0.691-0.795) and 0.762 (95% CI, 0.700-0.824), respectively. However, the best model for predicting preterm SGA < 3rd without pre-eclampsia was the combination of maternal factors and PlGF (AUC, 0.786 (95% CI, 0.723-0.849)). The FMF competing-risks model including maternal factors, MAP, UtA-PI and PlGF achieved detection rates of 42.2%, 47.3% and 48.1%, at a fixed false-positive rate of 10%, for the prediction of preterm SGA < 10th , preterm SGA < 5th and preterm SGA < 3rd , respectively. The calibration of the model was satisfactory.

CONCLUSION

The screening performance of the FMF first-trimester competing-risks model for SGA in a large, independent cohort of Asian women is comparable with that reported in the original FMF study in a mixed European population. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Change in client choice under multiple prenatal genetic testing options including noninvasive prenatal testing (NIPT) after genetic counseling in a Japanese maternity hospital

OBJECTIVE

This study examined how clients' selection and preference for noninvasive prenatal testing (NIPT) for aneuploidy changed with genetic counseling (GC) performed by certified geneticists at a primary hospital specializing in obstetrics, where other multiple prenatal genetic tests options were available.

METHODS

A total of 334 couples who underwent GC between 2017 and 2019 were included in the study. The average age of the pregnant women who underwent GC was 35.1 years.

RESULTS

Among the 95 couples (28.4%) who wanted NIPT at the start of GC, 10 (10.5%) switched to other tests, and 4 (4.2%) chose not to undergo any test. Among the 106 (31.7%) couples who wanted the combination of ultrasonography and the serum marker test, 12 (11.3%) chose not to undergo the test. Among the 92 (27.5%) couples who were undecided before GC, 21 (22.8%) wanted NIPT, 31 (33.7%) selected combined tests, and 18 (19.6%) did not undergo any test.

CONCLUSION

We have demonstrated the significance of GC before prenatal genetic testing under widespread use of NIPT. Ideally, obstetric facilities should provide GC, or at least, pre-counseling at their own facilities, and offer multiple prenatal genetic testing options or refer to other facilities for the same.

Aortic Dissection and a Previously Unreported ACTA2 Missense Variant Mutation in a Young Patient: A Case Report

Hereditary connective tissue disease is known to cause aortic lesions at an early age. Familial aortic aneurysm/dissection is caused due to an ACTA2 mutation that affects smooth muscle structure. We present a case of a 15-year-old boy with a mild developmental disorder in whom no abnormalities were identified on previous physical examinations. The patient presented with severe left heart failure, extensive dissection from the ascending aorta to the common iliac artery, and myocardial and cerebral infarctions. He underwent an urgent Bentall surgery. Six months later, the patient underwent surgical reconstruction of the abdominal aorta from the aortic arch and returned to normal daily activities. Pathological examination demonstrated the absence of elastic fibers but presence of abundant reticular fibers and mucopolysaccharides from the tunica intima to the media. Genetic testing revealed a heterozygous missense variant of the ACTA2 gene. To the best of our knowledge, this is the first sporadic case of structurally abnormal smooth muscle organization resulting in clinical symptoms with no previously reported pathogenicity.

Cat-Ear-Line: A Sonographic Sign of Cortical Development?

OBJECTIVES

Diagonal echogenic lines outside the lateral ventricle have often been observed in the anterior coronal planes of the normal fetal brain by neurosonography. We have observed abnormal shapes of these echogenic lines in cases of malformation of cortical development (MCD). We named the ultrasound finding "cat-ear-line" (CEL). This study aimed to examine how and when CEL develops in normal cases compared with MCD cases.

METHODS

We retrospectively examined the fetal brain volume dataset acquired through transvaginal 3D neurosonography of 575 control cases and 39 MCD cases from 2014 to 2020. We defined CEL as the hyperechogenic continuous lines through subplate (SP) and intermediate zone (IZ), pre-CEL as the lines that existed only within the SP, and abnormal CEL as a mass-like or mosaic shadow-like structure that existed across the SP and IZ. All fetuses in the MCD group had some neurosonographic abnormalities and were ultimately diagnosed with MCD.

RESULTS

The CEL was detected in 97.9% (369/377) of the control group from 19 to 30 weeks. The CEL visualization rate of the MCD group in the same period was 40.0% (14/35) which was significantly lower than that of the control group (P < .001).

CONCLUSIONS

From this study, it appears that the CEL is an ultrasound finding observed at and beyond 19 weeks in a normally developing fetus. In some MCD cases, pre-CEL at and beyond 19 weeks or abnormal CEL was observed. Maldeveloped CEL at mid-trimester may help identify cases at-risk of subsequent MCD.

First trimester examination of fetal anatomy: clinical practice guideline by the World Association of Perinatal Medicine (WAPM) and the Perinatal Medicine Foundation (PMF)

This recommendation document follows the mission of the World Association of Perinatal Medicine (WAPM) in collaboration with the Perinatal Medicine Foundation (PMF). We aim to bring together groups and individuals throughout the world for precise standardization to implement the ultrasound evaluation of the fetus in the first trimester of pregnancy and improve the early detection of anomalies and the clinical management of the pregnancy. The aim is to present a document that includes statements and recommendations on the standard evaluation of the fetal anatomy in the first trimester, based on quality evidence in the peer-reviewed literature as well as the experience of perinatal experts around the world.

Placental Types and Effective Perinatal Management of Vasa Previa: Lessons from 55 Cases in a Single Institution

BACKGROUND

We aimed to identify clinical characteristics and outcomes for each placental type of vasa previa (VP).

METHODS

Placental types of vasa previa were defined as follows: Type 1, vasa previa with velamentous cord insertion and non-type 1, vasa previa with a multilobed or succenturiate placenta and vasa previa with vessels branching out from the placental surface and returning to the placental cotyledons.

RESULTS

A total of 55 cases of vasa previa were included in this study, with 35 cases of type 1 and 20 cases of non-type 1. Vasa previa with type 1 showed a significantly higher association with assisted reproductive technology, compared with non-type 1 (p = 0.024, 60.0% and 25.0%, respectively). The diagnosis was significantly earlier in the type 1 group than in the non-Type 1 group (p = 0.027, 21.4 weeks and 28.6 weeks, respectively). Moreover, the Ward technique for anterior placentation to avoid injury of the placenta and/or fetal vessels was more frequently required in non-type 1 cases (p < 0.001, 60.0%, compared with 14.3% for type 1).

CONCLUSION

The concept of defining placental types of vasa previa will provide useful information for the screening of this serious complication, improve its clinical management and operative strategy, and achieve more preferable perinatal outcomes.

First-trimester pre-eclampsia biomarker profiles in Asian population: multicenter cohort study

OBJECTIVES

To (i) evaluate the applicability of the European-derived biomarker multiples of the median (MoM) formulae for risk assessment of preterm pre-eclampsia (PE) in seven Asian populations, spanning the east, southeast and south regions of the continent, (ii) perform quality-assurance (QA) assessment of the biomarker measurements and (iii) establish criteria for prospective ongoing QA assessment of biomarker measurements.

METHODS

This was a prospective, non-intervention, multicenter study in 4023 singleton pregnancies, at 11 to 13 + 6 weeks' gestation, in 11 recruiting centers in China, Hong Kong, India, Japan, Singapore, Taiwan and Thailand. Women were screened for preterm PE between December 2016 and June 2018 and gave written informed consent to participate in the study. Maternal and pregnancy characteristics were recorded and mean arterial pressure (MAP), mean uterine artery pulsatility index (UtA-PI) and maternal serum placental growth factor (PlGF) were measured in accordance with The Fetal Medicine Foundation (FMF) standardized measurement protocols. MAP, UtA-PI and PlGF were transformed into MoMs using the published FMF formulae, derived from a largely Caucasian population in Europe, which adjust for gestational age and covariates that affect directly the biomarker levels. Variations in biomarker MoM values and their dispersion (SD) and cumulative sum tests over time were evaluated in order to identify systematic deviations in biomarker measurements from the expected distributions.

RESULTS

In the total screened population, the median (95% CI) MoM values of MAP, UtA-PI and PlGF were 0.961 (0.956-0.965), 1.018 (0.996-1.030) and 0.891 (0.861-0.909), respectively. Women in this largely Asian cohort had approximately 4% and 11% lower MAP and PlGF MoM levels, respectively, compared with those expected from normal median formulae, based on a largely Caucasian population, whilst UtA-PI MoM values were similar. UtA-PI and PlGF MoMs were beyond the 0.4 to 2.5 MoM range (truncation limits) in 16 (0.4%) and 256 (6.4%) pregnancies, respectively. QA assessment tools indicated that women in all centers had consistently lower MAP MoM values than expected, but were within 10% of the expected value. UtA-PI MoM values were within 10% of the expected value at all sites except one. Most PlGF MoM values were systematically 10% lower than the expected value, except for those derived from a South Asian population, which were 37% higher.

CONCLUSIONS

Owing to the anthropometric differences in Asian compared with Caucasian women, significant differences in biomarker MoM values for PE screening, particularly MAP and PlGF MoMs, were noted in Asian populations compared with the expected values based on European-derived formulae. If reliable and consistent patient-specific risks for preterm PE are to be reported, adjustment for additional factors or development of Asian-specific formulae for the calculation of biomarker MoMs is required. We have also demonstrated the importance and need for regular quality assessment of biomarker values. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Prospective evaluation of screening performance of first-trimester prediction models for preterm preeclampsia in an Asian population

BACKGROUND

The administration of aspirin <16 weeks gestation to women who are at high risk for preeclampsia has been shown to reduce the rate of preterm preeclampsia by 65%. The traditional approach to identify such women who are at risk is based on risk factors from maternal characteristics, obstetrics, and medical history as recommended by the American College of Obstetricians and Gynecologists and the National Institute for Health and Care Excellence. An alternative approach to screening for preeclampsia has been developed by the Fetal Medicine Foundation. This approach allows the estimation of patient-specific risks of preeclampsia that requires delivery before a specified gestational age with the use of Bayes theorem-based model.

OBJECTIVE

The purpose of this study was to examine the diagnostic accuracy of the Fetal Medicine Foundation Bayes theorem-based model, the American College of Obstetricians and Gynecologists, and the National Institute for Health and Care Excellence recommendations for the prediction of preterm preeclampsia at 11-13⁺⁶ weeks gestation in a large Asian population STUDY DESIGN: This was a prospective, nonintervention, multicenter study in 10,935 singleton pregnancies at 11-13⁺⁶ weeks gestation in 11 recruiting centers across 7 regions in Asia between December 2016 and June 2018. Maternal characteristics and medical, obstetric, and drug history were recorded. Mean arterial pressure and uterine artery pulsatility indices were measured according to standardized protocols. Maternal serum placental growth factor concentrations were measured by automated analyzers. The measured values of mean arterial pressure, uterine artery pulsatility index, and placental growth factor were converted into multiples of the median. The Fetal Medicine Foundation Bayes theorem-based model was used for the calculation of patient-specific risk of preeclampsia at <37 weeks gestation (preterm preeclampsia) and at any gestation (all preeclampsia) in each participant. The performance of screening for preterm preeclampsia and all preeclampsia by a combination of maternal factors, mean arterial pressure, uterine artery pulsatility index, and placental growth factor (triple test) was evaluated with the adjustment of aspirin use. We examined the predictive performance of the model by the use of receiver operating characteristic curve and calibration by measurements of calibration slope and calibration in the large. The detection rate of screening by the Fetal Medicine Foundation Bayes theorem-based model was compared with the model that was derived from the application of American College of Obstetricians and Gynecologists and National Institute for Health and Care Excellence recommendations.

RESULTS

There were 224 women (2.05%) who experienced preeclampsia, which included 73 cases (0.67%) of preterm preeclampsia. In pregnancies with preterm preeclampsia, the mean multiples of the median values of mean arterial pressure and uterine artery pulsatility index were significantly higher (mean arterial pressure, 1.099 vs 1.008 [P<.001]; uterine artery pulsatility index, 1.188 vs 1.063[P=.006]), and the mean placental growth factor multiples of the median was significantly lower (0.760 vs 1.100 [P<.001]) than in women without preeclampsia. The Fetal Medicine Foundation triple test achieved detection rates of 48.2%, 64.0%, 71.8%, and 75.8% at 5%, 10%, 15%, and 20% fixed false-positive rates, respectively, for the prediction of preterm preeclampsia. These were comparable with those of previously published data from the Fetal Medicine Foundation study. Screening that used the American College of Obstetricians and Gynecologists recommendations achieved detection rate of 54.6% at 20.4% false-positive rate. The detection rate with the use of National Institute for Health and Care Excellence guideline was 26.3% at 5.5% false-positive rate.

CONCLUSION

Based on a large number of women, this study has demonstrated that the Fetal Medicine Foundation Bayes theorem-based model is effective in the prediction of preterm preeclampsia in an Asian population and that this method of screening is superior to the approach recommended by American College of Obstetricians and Gynecologists and the National Institute for Health and Care Excellence. We have also shown that the Fetal Medicine Foundation prediction model can be implemented as part of routine prenatal care through the use of the existing infrastructure of routine prenatal care.

Transvaginal three-dimensional ultrasound assessment of Sylvian fissures at 18-30 weeks' gestation

OBJECTIVE

To (1) evaluate the normal development of the Sylvian fissures in the anterior coronal view of the fetal brain at 18-30 weeks' gestation by transvaginal three-dimensional (3D) ultrasound, (2) develop reference ranges of measurements of the right and left Sylvian fissure angles during normal pregnancy at 18-30 weeks' gestation, and (3) examine intra- and interobserver repeatability of measurements of the right and left Sylvian fissure angles.

METHODS

This was a prospective cross-sectional study of 422 women with a singleton pregnancy attending an ultrasound-based research clinic between March and December 2017. The entry criteria for the study were appropriately grown live fetus with no suspected structural and/or chromosomal defects between 18 + 0 and 30 + 6 weeks' gestation. Normal development of the Sylvian fissures was assessed in the anterior coronal plane of the fetal brain using transvaginal 3D volume multiplanar imaging. The coronal view was visualized as a single image from the three orthogonal views. Subsequently, the right and left Sylvian fissure angles were measured between a horizontal reference line (0°) and a line drawn along the upper side of the respective Sylvian fissure. Intra- and interobserver repeatability of the Sylvian fissure angle measurements was assessed by Bland-Altman plots. Reference equations were constructed for right and left Sylvian fissure angles for gestational age (GA) and head circumference (HC) using the Generalized Additive Models for Location Scale and Shape package.

RESULTS

In the anterior coronal view of the fetal brain, an inward rotation of the upper portion of the Sylvian fissures was observed during the second and third trimesters of pregnancy. There was a significant negative polynomial association between the Sylvian fissure angles and GA and HC. Both Sylvian fissure angles crossed the reference line (zero), going from positive to negative, at around 25 weeks' gestation or at HC of 22 cm. Z-score difference between the smoothed percentiles of the right and left Sylvian fissure angles indicated that median, 10^th and 90^th smoothed percentiles were closest and almost the same for the GA-based references between 18 and 28 weeks and for the HC-based references between 14 and 24 cm. The intraclass correlation coefficient of the right and left Sylvian fissure angle measurements between the two sonographers was excellent at 0.993 (95% CI, 0.988-0.996) and 0.991 (95% CI, 0.985-0.995), respectively. On Bland-Altman analysis, the mean difference between the two sonographers in right Sylvian fissure angle measurement was 0.4° (95% CI, -10.2 to 10.1°) and in left Sylvian fissure angle it was 1.0° (95% CI, -9.6 to 11.6°).

CONCLUSIONS

Assessment of the Sylvian fissure angles is highly reproducible. Sylvian fissure angle reference charts can serve as a screening tool for malformations of cortical development, guiding subsequent follow-up and referral for fetal brain magnetic resonance imaging and/or assessment by an expert neurosonologist. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

3D/4D sonography - any safety problem

Gray-scale image data are processed in 3D ultrasound by repeated scans of multiple planes within a few seconds to achieve one surface rendering image and three perpendicular plane images. The 4D image is achieved by repeating 3D images in short intervals, i.e. 3D and 4D ultrasound are based on simple B-mode images. During 3D/4D acquisition, a fetus in utero is exposed by ultrasound beam for only a few seconds, and it is as short as real-time B-mode scanning. Therefore, simple 3D imaging is as safe as a simple B-mode scan. The 4D ultrasound is also as safe as a simple B-mode scan, but the ultrasound exposure should be shorter than 30 min. The thermal index (TI) and mechanical index (MI) should both be lower than 1.0, and the ultrasound study is regulated by the Doppler ultrasound if it is combined with simple 3D or 4D ultrasound. Recently, some articles have reported the functional changes of animal fetal brain neuronal cells and liver cell apoptosis with Doppler ultrasound. We discuss cell apoptosis by ultrasound in this report. Diagnostic ultrasound safety is achieved by controlling the output pulse and continuous ultrasound waves using thermal and mechanical indices, which should be <1.0 in abdominal and transvaginal scan, pulsed Doppler, as well as 3D and 4D ultrasound. The lowest spatial peak temporal average (SPTA) intensity of the ultrasound to suppress cultured cell growth is 240 mW/cm2, below which no ultrasound effect has been reported. An ultrasound user must be trained to recognize the ultrasound bioeffects; thermal and mechanical indices, and how to reduce these when they are higher than 1.0 on the monitor display; and guide the proper use of the ultrasound under the ALARA principle, because the user is responsible for ensuring ultrasound safety.

Three-dimensional Ultrasound in Detection of Fetal Anomalies

In the history of 3D/4D ultrasound technology, the great achievement was high definition (HD) live technology. This technology is a novel ultrasound technique that improves the 3D/4D images. HDlive ultrasound has resulted in remarkable progress in visualization of early embryos and fetuses and in the development of sonoembryology. HDlive uses an adjustable light source and software that calculates the propagation of light through surface structures in relation to the light direction. The virtual light source produces selective illumination, and the respective shadows are created by the structures where the light is reflected. This combination of light and shadows increases depth perception and produces remarkable images that are more natural than those obtained with classic three-dimensional (3D) ultrasound. The virtual light can be placed in the front, back, or lateral sides, where viewing is desired until the best image is achieved. A great advantage is that the soft can be applied to all images stored in the machine's memory. With HDlive ultrasound, both structural and functional developments can be assessed from early pregnancy more objectively and reliably and, indeed, the new technology has moved embryology from postmortem studies to the in vivo environment. Practically, in obstetrical ultrasound, HDlive could be used during all three trimesters of pregnancy.

How to cite this article

Pooh RK, Kurjak A. Three-dimensional Ultrasound in Detection of Fetal Anomalies. Donald School J Ultrasound Obstet Gynecol 2016;10(3):214-234.

A New Field of ‘Fetal Sono-ophthalmology’ by 3D HDlive Silhouette and Flow

Diagnostic ultrasound technology has remarkably evolved and contributed to accurate prenatal diagnosis and management. HDlive silhouette and HDlive flow are new applications of threedimensional (3D) ultrasound technology. The algorism of HDlive silhouette creates a gradient at organ boundaries where an abrupt change of the acoustic impedance exists within tissues. HDlive silhouette and flow can be called as ‘see-through fashion’. The advantages of this ‘see-through fashion’ imaging are comprehensive orientation and persuasive localization of inner structure as well as of fetal angiostructure inside the morphological structure. Picture of the month demonstrates the fetal eye at 19 weeks of gestation. The lens, vitreous body and hyaloid artery inside the vitreous humor are well demonstrated. The hyaloid artery is retrogressing during pregnancy and no remnant hyaloid artery is visible in most of mature neonates. Therefore, hyaloid artery can be observed in only young fetuses and immature neonates. HDlive silhouette and flow has enabled us to depict fetal eye and ocular vascularity three-dimensionally. This new technology has a great potential to open a new field of ‘fetal 3D sono-ophthalmology’, which has been never invented by conventional ultrasound technology.

How to cite this article

Pooh RK. A New Field of ‘Fetal Sonoophthalmology’ by 3D HDlive Silhouette and Flow. Donald School J Ultrasound Obstet Gynecol 2015;9(3):221-222.

‘See-through Fashion’ in Prenatal Diagnostic Imaging

Three-dimensional (3D) ultrasound has remarkably contributed to prenatal diagnosis in fetal medicine. New applications of HDlive silhouette and HDlive flow show an inner cystic structure through the outer surface structure of the body and it can be appropriately named as ‘see-through fashion’. Picture of the month demonstrates the premature brain cavity of forebrain, midbrain and hindbrain as well as the fetal premature central nervous system vascularity toward the brain inside the outer surface structure of an 8-week-fetus. Thus, the advantages of this ‘see-through fashion’ imaging are comprehensive orientation and persuasive localization of inner morphological structure as well as of fetal angiostructure, and more accurate clinical information for prenatal diagnoses and proper perinatal management can be added.

How to cite this article

Pooh RK. ‘See-through Fashion’ in Prenatal Diagnostic Imaging. Donald School J Ultrasound Obstet Gynecol 2015;9(2):111.

Imaging diagnosis of congenital brain anomalies and injuries

Fetal brain is rapidly developing and changing its appearance week by week during pregnancy. The brain is the most important organ but it is quite hard to observe detailed structure of this organ by conventional transabdominal sonography. Transvaginal high-resolution ultrasound and three-dimensional (3D) ultrasound has been a great diagnostic tool for evaluation of three-dimensional structure of fetal central nervous system (CNS). This method has contributed to the prenatal assessment of congenital CNS anomalies, intracranial vascular anomalies and acquired brain damage in utero. It is possible to observe the whole brain structure by magnetic resonance imaging in the post half of pregnancy but transvaginal high-resolution 3D ultrasound is certainly powerful modality as well for understanding brain anatomy. Longitudinally and carefully evaluation of neurological short- or long-term prognosis should be required according to precise prenatal diagnosis, for proper counseling and management based on precise evidence.

Molecular genetics in fetal neurology

Brain malformations, particularly related to early brain development, are a clinically and genetically heterogeneous group of fetal neurological disorders. Fetal cerebral malformation, predominantly of impaired prosencephalic development namely agenesis of the corpus callosum and septo-optic dysplasia, is the main pathological feature in fetus, and causes prominent neurodevelopmental retardation, and associated with congenital facial anomalies and visual disorders. Differential diagnosis of brain malformations can be extremely difficult even through magnetic resonance imaging. Advances in genomic and molecular genetics technologies have led to the identification of the sonic hedgehog pathways and genes critical to the normal brain development. Molecular cytogenetic and genetic studies have identified numeric and structural chromosomal abnormalities as well as mutations in genes important for the etiology of fetal neurological disorders. In this review, we update the molecular genetics findings of three common fetal neurological abnormalities, holoprosencephaly, lissencephaly and agenesis of the corpus callosum, in an attempt to assist in perinatal and prenatal diagnosis.

Sonogenetics in fetal neurology

Fetal imaging technology has been advancing remarkably and prenatal detection and diagnoses have been moved forward from the second and third trimesters to the first trimester. Structural abnormalities detected by fetal imaging often lead to prenatal diagnoses of genetic disorders. However, there are still dilemmas in fetal diagnoses in normal karyotype cases with strong suspicion of congenital genetic disorders from sonographic findings. When fetal sonography reveals multiple minor abnormalities originating from various organs, counseling dilemmas and parental anxieties become greater than before karyotyping. Array-comparative genomic hybridization (aCGH) was developed as a high-resolution analysis of DNA copy number variations (CNVs). In seven cases presenting with abnormal brain structures by fetal imaging, abnormal CNVs were confirmed by aCGH but conventional karyotyping yielded normal results. Although careful patient selection is required in order to deal with microarray results and parental counseling, 'sonogenetics' - incorporating the idea of 'fetuses first' - will play an important role in the era of molecular genetics. Recent advances in non-invasive prenatal testing by using fetal cell-free DNA in maternal plasma has the potential to generate misleading prenatal diagnoses without the observation of fetuses. However, no fetal diagnoses should be made without observing fetuses and we must not forget 'the fetus as a patient'.

Diagnosis, treatment, and long-term outcomes of fetal hydrocephalus

This study analyzed 156 cases of fetal hydrocephalus treated at Osaka National Hospital from 1992 to 2011 to review current methods for diagnosing and treating fetal hydrocephalus, and for estimating its clinical outcome. This was a retrospective study of a single institute (Osaka National Hospital). Of 156 cases in total, 37% were diagnosed as isolated ventriculomegaly, 50% as another type of malformation (36 cases of myelomeningocele, six of holoprosencephaly, three of Dandy-Walker syndrome, one case of Joubert syndrome, 12 of arachnoid cyst, nine of encephalocele, three of atresia of Monro and eight of corpus callosum agenesis, and 13% as secondary hydrocephalus. Diagnoses were made between 13 and 40 weeks of gestation (average 27 weeks). Diagnosis was made before 21 weeks of gestation in 24% of cases, from the first day of 22 weeks to the sixth day of 27 weeks in 27%, and after the first day of 28 weeks in 49%. With the exclusion of 17 aborted cases and 40 cases in which the patients were too young to evaluate or lost during follow-up, the final outcome was analyzed for 90 cases. Of these, 17% of the patients died, 21% showed severe retardation, 13% moderate retardation, 26% mild retardation, and 23% showed a good outcome. The long-term outcome was mostly influenced by the basic disease and accompanying anomaly. The time of diagnosis showed no correlation with outcome. Hydrocephalus associated with arachnoid cyst, atresia of Monro, and corpus callosum agenesis, and hydrocephalus due to fetal intracranial hemorrhage, resulted in good outcomes. By contrast, holoprosencephaly, hydrocephalus associated with encephalocele, syndromic hydrocephalus, and hydrocephalus due to fetal virus infection led to poor outcomes. For accurate diagnosis and proper counseling, established protocols are important for the diagnosis and treatment of fetal hydrocephalus, including not only fetal sonography, fetal magnetic resonance imaging, and TORCH (toxoplasma, rubella, cytomegalovirus, herpes simplex) screening test, but also chromosomal and gene testing.

Normal anatomy by three-dimensional ultrasound in the second and third trimesters

Fetal brain is rapidly developing and changing its appearance week by week during pregnancy. It is quite difficult to observe detailed structure of the brain by conventional transabdominal sonography. Transvaginal high-resolution ultrasound and three-dimensional (3D) ultrasound have been establishing sonoembryology in the first trimester as well as neurosonography. It is possible to observe the whole brain structure by magnetic resonance imaging in the latter half of pregnancy but transvaginal high-resolution 3D ultrasound is also a powerful modality for understanding brain anatomy. As for brain vascularization, main arteries and veins have been demonstrated and evaluated in various central nervous system conditions. Transvaginal high-resolution 3D ultrasound can demonstrate even cerebral fine vascular anatomy such as medullary vessels and it is greatly expected to estimate neurological prognosis in relation to vascular development during the fetal period.

Non-invasive prenatal screening of fetal sex chromosomal abnormalities: perspective of pregnant women

OBJECTIVE

To study whether pregnant women would like to be informed if sex chromosomal abnormalities (SCA) were suspected with the non-invasive prenatal diagnosis of fetal Down syndrome (the NIFTY) test.

METHODS

Two hundred and one patients carried a singleton pregnancy requesting the NIFTY test were invited to give their preferences if there was suspicion of SCA by the NIFTY test.

RESULTS

Over 93.5% were ethnic Chinese, with a mean age of 36. Prior Down screening was positive in 66 (32.8%). Over 50% of subjects considered SCA to be better in terms of disability compared to Down syndrome, and only 5.2% considered SCA to be worse. Yet, the majority (198, 98.5%) indicated that they wanted to be informed if there was suspicion of SCA. Of whom 34.8% would have an amniocentesis for confirmation, while 57.1% were not certain, indicating the possibility of accepting these conditions.

CONCLUSION

Besides screening Down syndrome by NIFTY, most pregnant women would also like to be informed if there was suspicion of SCA. Those screened positive should be counseled by those with experience in genetics to avoid unnecessary pregnancy termination.

Clinical utility of noninvasive fetal trisomy (NIFTY) test--early experience

Objective: To report the initial experience of noninvasive prenatal diagnosis of fetal Down syndrome (The NIFTY test) in a clinical setting. Methods: The NIFTY test was offered as a screening test for fetal Down syndrome to pregnant women with a singleton pregnancy at 12 weeks of gestation or beyond. A satisfaction questionnaire was sent to the first 400 patients. Results: During a 6-month period, 567 NIFTY tests were performed. Over 90% of those studied were ethnic Chinese, and the mean age of the women studied was 36 years. The test was performed at 12–13 weeks of gestation in 49.21%. The median reporting time was 9 days. The test was positive for trisomy 21 in eight cases, and for trisomy 18 in 1 case; all were confirmed by fetal karyotyping. There was no false-positive result. Of the questionnaires, 182 completed responses were received. Over 95% had complete or almost complete resolution of anxiety. Except for one, all were satisfied with the NIFTY test, and all indicated that they would recommend the test to their friends. Conclusion: The NIFTY test was a highly specific test. Unnecessary invasive tests and associated fetal losses could be avoided in almost all women who have a normal fetus.

Prenatal molecular diagnosis of a severe type of L1 syndrome (X-linked hydrocephalus)

OBJECT

The aim of this study was to evaluate the feasibility of prenatal L1CAM gene testing for X-linked hydrocephalus (XLH).

METHODS

In a nationwide study conducted in Japan between 1999 and 2009, the authors identified 51 different L1CAM gene mutations in 56 families with XLH. Of these 56 families, 9 obligate carriers requested prenatal gene mutation analysis for the fetal L1CAM gene in 14 pregnancies.

RESULTS

In 2004, new clinical guidelines for genetic testing were established by 10 Japanese genetic medicine-related societies. These guidelines stated that the genetic testing of carriers should be done only with their consent and with genetic counseling. Therefore, because females are carriers, since 2004, L1CAM gene analysis has not been performed for female fetuses. The authors report on 7 fetal genetic analyses that were performed at the request of families carrying L1CAM mutations, involving 3 female (prior to 2004) and 4 male fetuses. Of the 7 fetuses, 3 (1 male and 2 female) carried L1CAM mutations. Of these 3, 1 pregnancy (the male fetus) was terminated; in the other cases, the pregnancies continued, and 3 female and 3 male babies without the XLH phenotype were born.

CONCLUSIONS

Prenatal L1CAM gene testing combined with genetic counseling was beneficial for families carrying L1CAM mutations.

3D and 4D sonography and magnetic resonance in the assessment of normal and abnormal CNS development: alternative or complementary

Advanced transvaginal neurosonography has revealed normal and abnormal intracranial morphology. Transvaginal three-dimensional (3D) sonography demonstrates bony structure, multiplanar analysis of inside detailed morphology, tomographic ultrasound imaging in any cutting sections, 3D sonoangiography and volume calculation of ventricles and/or intracranial lesions. Longitudinal assessment of normal and abnormal central nervous system (CNS) development is done by serial scanning. However, the transvaginal high-frequency approach has several limitations due to lack of penetration and cranial bone ossification with advanced gestational age. Magnetic resonance neuroimaging enabled observation of the whole intracranial cavity, brainstem and cortical gyral/sulcal development. On the other hand, neuro-sonography has advantages in detecting intracranial calcification, vascular abnormalities, intratumoral vascularity and bone dysplasia. Moreover, 3D ultrasound demonstrates extra CNS abnormalities, strongly associated with CNS abnormalities. Any less-invasive modalities can be used for a CNS anomaly screening scan and ultrasound is no doubt the first choice. Once CNS abnormality is suspected, it is suggested to use the different technologies according to what is looked for in each abnormal CNS case. Of course, MR and 3D ultrasound imaging should be complementary as well as alternative.

Imaging of the human embryo with magnetic resonance imaging microscopy and high-resolution transvaginal 3-dimensional sonography: human embryology in the 21st century

OBJECTIVE

This article illustrates early human development, demonstrated by magnetic resonance (MR) microscopy and computer graphics on human embryo specimens, and advanced 3-dimensional (3D) sonography in clinical obstetrics.

STUDY DESIGN

Fixed human embryo specimens were imaged by MR microscopy coupled with computer graphics technology. Transvaginal 3D sonography was used to examine embryos in ongoing gestations and compare embryological findings.

RESULTS

Advances in MR microscopy allowed detailed visualization of embryo specimens. Computational techniques allowed reconstruction of tomographic images to render them as 3D structures. High-resolution transvaginal 3D sonography produced images that demonstrated the neural tube from week 6; brain anatomy and vasculature from week 8; and craniofacial morphology and other structures from week 11.

CONCLUSION

MR microscopy is a novel technique that enables nondestructive, high-resolution imaging of embryo specimens. On the other hand, 3D sonoembryology allows detailed anatomical visualization in vivo and is the basis for the assessment of anomalies as well as human development.

Classification of pathogenic or benign status of CNVs detected by microarray analysis

Multiple lines of evidence indicated that microarray analysis has a better diagnostic yield of clinically significant genetic changes than do conventional methods in patients with constitutional abnormalities. However, interpretation of microarray data is complicated by the presence of both novel and recurrent copy number variants (CNVs) of unknown significance. To address this issue, Hehir-Kwa et al. described a new computational method for determining the pathogenicity between benign and mental retardation (MR)-associated CNVs among patients with MR. This study demonstrated the value of objectively prioritizing MR-associated CNVs using structural and functional genomic features in diagnostics. In this regard, we discuss an evidence-based summary of how to classify pathogenic or benign status of a CNV in clinical genetics and advocate that there is a need for algorithmic adjustment between constitutional cytogenetic and prenatal diagnosis settings.

The potential of 4D sonography in the assessment of fetal neurobehavior--multicentric study in high-risk pregnancies

OBJECTIVE

An evolving challenge for obstetrician is to better define normal and abnormal fetal neurological function in utero in order to better predict antenatally which fetuses are at risk for adverse neurological outcome.

PATIENTS AND METHODS

Prenatal neurological assessment in high-risk fetuses using four-dimensional ultrasound applying the recently developed Kurjak antenatal neurodevelopmental test (KANET). Postnatal neurological assessment was performed using Amiel Tison's neurological assessment at term (ATNAT) for all live-borns and general movement (GM) assessment for those with borderline and abnormal ATNAT.

RESULTS

Inclusion criteria were met by 288 pregnant women in four centers of whom 266 gave birth to a live-born baby. It was revealed that 234 fetuses were neurologically normal, 7 abnormal and 25 borderline. Out of 7 abnormal fetuses ATNAT was borderline in 5 and abnormal in 2, whereas GM assessment was abnormal in 5 and definitely abnormal in 2. Out of 25 KANET borderline fetuses, ATNAT was normal in 7, borderline in 17 and abnormal in 1, whereas the GM assessment was as follows: normal optimal in 4, normal suboptimal in 20, and abnormal in 1. In summary, out of 32 borderline and abnormal fetuses ATNAT was normal in 7, borderline in 22 and abnormal in 3; GM assessment was normal optimal in 4, normal suboptimal in 20, abnormal in 6 and definitely abnormal in 2.

CONCLUSION

The sonographic test requires further studies before being recommended for wider clinical practice.

Detailed multigrade evaluation of fetal disorders with the quantified actocardiogram

AIMS

To evaluate fetal disorders using detailed quantitative values from the actocardiogram (ACG) involving simultaneous tracing of ultrasonic Doppler fetal movement bursts and fetal heart rate (FHR).

METHODS

Duration of FHR accelerations and fetal movement bursts were measured manually in 20 common fetal disorders. The severity of the fetal disorder was estimated using the FHR acceleration duration to movement burst ratio (A/B ratio) and 10-0 clinical severity ranks derived from the A/B ratio. The correlation of the A/B ratio and 1 and 5 min Apgar scores, as well as numerically expressed long-term outcomes were studied.

RESULTS

A/B ratios were significantly correlated with the 1 and 5 min Apgar scores and the numerically evaluated long-term outcomes. Controversial cases of FHR pattern were more easily understood using the A/B ratio. The 10-0 severity derived from the A/B ratio was useful in clinical fetal studies.

CONCLUSION

Common fetal disorders were evaluated quantitatively and in more detail using the A/B ratio from the actocardiogram than when using common binary good or bad evaluation. The A/B ratio was useful in outcome estimation, where the prognostic capability of the A/B ratio was confirmed by significant correlation with 1 and 5 min Apgar scores and long-term outcomes of fetal disorders.

Advances in Visualization of the Early Human Development

The anatomy and physiology of placental and embryonic development is a field where medicine exerts its impact on early pregnancy and opens fascinating aspects of embryonic differentiation. The introduction of high frequency transvaginal transducers as well as three and four dimensional sonography has resulted in remarkable progress in ultrasonic visualization of early embryos and fetuses.

Ultrasound has been widely used in the field of early human development due to its safety, diagnostic accuracy and convenience. Normal fetal anatomy and development have been widely investigated using two-dimensional ultrasound and most of the knowledge regarding early human development were established through understanding of sectional images of fetal body and organs obtained by two-dimensional ultrasound. Usage of new techniques has produced more objective and accurate information of embryonal and early fetal development. For the first time parallel analyses of structural and functional parameters in the first 12 weeks of gestation become possible. This article deals with establishment of human life from ovum and sperm, though fertilization, detailed histological development and the establishment of the placenta, and early human development visualized by 2- and 3-dimensional ultrasonography.

Fetal behavior analyzed by ultrasonic actocardiogram in cases with central nervous system lesions

AIMS

This study examined whether analysis of fetal behavioral states by monitoring fetal heart rate and movement using an actocardiogram (ACG), could provide prognostic information related to fetal central nervous system (CNS) lesions.

METHODS

The ACG simultaneously records fetal heart rate (FHR) and fetal movement bursts composed of spikes of ultrasonic Doppler signals. Durations of FHR accelerations and fetal movement bursts were measured manually. Five actocardiographic indices were studied in 12 fetuses with CNS lesions and in 14 normal pregnancies of 28-38 weeks.

RESULTS

Severity of the fetal CNS lesions was estimated from the acceleration/burst (A/B) duration ratio, which correlated with the rank of the sonographic fetal functional test in cases with CNS lesions. Severity of a fetal lesion may also be estimated by the regression equation of the A/B duration ratio and behavioral ranking.

CONCLUSION

The severity of fetal CNS lesions may be estimated by quantitative analysis of ACG usings the measurement of A/B duration ratio to provide a prognosis. An ACG may demonstrate a loss of CNS control in cases with severe brain damage.

Fetal Ventriculomegaly

The causes of fetal ventriculomegaly vary. Ventriculomegaly can be caused by not only obstruction of cerebrospinal flow tract but also brain maldevelopment or other reasons. Recent advanced imaging technology and approaching technique of transvaginal sonography have contributed to an accurate prenatal diagnosis and clearly revealed fetal intracranial condition. However, management of the condition and counseling of parents are still difficult, because the initial cause, absolute risk, and degree of resulting neurological deficit cannot be determined with confidence. Ventriculomegaly is evaluated according to atrial width > 10 mm and mild ventriculomegaly is defined as an atrial width of 10 to 15 mm. In ventriculomegaly cases, accurate detection of intracranial structure and additional abnormalities is required. Furthermore, ventriculomegaly may resolve spontaneously or progress during pregnancy. Therefore, detailed neuroscan by advanced imaging technology, detailed extra-CNS scan, longitudinal serial scan during pregnancy are mandatory for proper counseling and management. Longitudinal observation study of not only short-term but also long-term neurological prognosis will be required.

Structural and functional early human development assessed by three-dimensional and four-dimensional sonography

OBJECTIVE

To summarize the role of three-dimensional and four-dimensional ultrasound in the assessment of early human development.

DESIGN

Review of literature.

SETTING

Ultrasound research center and obstetrics and gynecology department in a tertiary care facility.

RESULT(S)

The introduction of high-frequency transvaginal tranducers has resulted in remarkable progress in ultrasonographic visualization of early embryos and fetuses and the development of sonoembryology. Furthermore, recent introduction of three-dimensional and four-dimensional ultrasounds combined with the transvaginal approach has produced more objective and accurate information on embryonal and early fetal development. For the first time parallel analyses of structural and functional parameters in the first 12 weeks of gestation become possible.

CONCLUSION(S)

The anatomy and physiology of placental and embryonic development is a field where medicine exerts its greatest impact on early pregnancy at present time, and it opens fascinating aspects of embryonic differentiation. Clinical assessment of those stages of growth rely heavily on three-dimensional and four-dimensional sonography, one of the most promising forms of noninvasive diagnostics today and embryological phenomenon, once matters for textbooks are now routinely recorded with outstanding clarity.

B-flow and B-flow spatio-temporal image correlation in visualizing fetal cardiac blood flow

AIM

To evaluate the clinical usefulness of two-dimensional B-flow imaging and four-dimensional (4D) B-flow spatio-temporal image correlation (STIC) as real-time three-dimensional technology in visualizing fetal cardiac blood flow.

METHOD

We examined 65 normal singleton fetuses between 21 and 39 weeks of gestation, using VOLUSON 730 Expert ultrasound device with transabdominal 3D/4D transducer. After visualizing fetal cardiac blood flow by two dimensional B-flow mode, B-flow STIC images were acquired .The acquisition angle was 40 degrees and acquisition time 15 s. The cardiac vascular system was analyzed off-line on multiplanar and reconstructed 3D/4D rendered images.

RESULTS

In 38 out of 65 cases, all extracardiac vessels of aortic arch, descending aorta, inferior vena cava, ductus venosus and hepatic vein could be detected on reconstructed 3D/4D images. In all 65 cases, two or more pulmonary veins were easily depicted. On a cardiac back-front view created by rotating 4D reconstructed image, two pulmonary veins among a total of four were depicted in 34 cases (52.3%), three veins in 28 cases (43.1%) and all four pulmonary veins in three cases (4.6%).

CONCLUSION

B-flow and/or B-flow STIC allow visualization of fine small vessels with low velocity, such as pulmonary veins, and may have a great potential for detailed detection of an abnormality of small cardiac vessels, such as total anomalous pulmonary venous return.

The assessment of fetal brain morphology and circulation by transvaginal 3D sonography and power Doppler

OBJECTIVE

The objective of this article is to describe the use of transvaginal 3D ultrasound in prenatal neuroimaging and to investigate its clinical usefulness.

METHODS

Firstly, 18 fetuses with hydrocephalus, ventriculomegaly and/or space occupying lesion were examined by transvaginal 3D sonography, and fetal CNS abnormalities were evaluated. Multiplanar image analysis and volumetric assessment were performed off-line. Longitudinal volume changes of target structure were evaluated, and usefulness of transvaginal 3D ultrasound was evaluated. Secondly, in 56 normal cephalic fetuses of between 18 and 32 weeks, 3D Doppler volume acquisition and reconstruction of the intracranial vascular structure were performed.

RESULTS

Longitudinal changing appearance in the same cutting section of the enlarged ventricle or cystic lesion could be demonstrated in all cases and volumetric assessment was also successful in all cases. Longitudinal objective data were useful in the brain assessment, consultation and counselling. 3D Doppler acquisition time was 5.6-26 seconds and symmetrical 3D reconstruction was successful in 51.8%.

CONCLUSION

Transvaginal 3D imaging technology provides us with not only comprehensive intracranial images in exactly the right sections, but also with objective volume data. Prenatal information with objective data analyses is useful in consultation for both specialists and parents, and leads to proper management of CNS diseases.