Prenatal diagnosis of alobar holoprosencephaly by two-dimensional and three-dimensional ultrasound

Prenatal Imaging of Supratentorial Fetal Brain Malformation

This review article provides a comprehensive overview of fetal MR imaging in supratentorial cerebral malformations. It emphasizes the importance of fetal MR imaging as an adjunct diagnostic tool used alongside ultrasound, improving the detection and characterization of prenatal brain abnormalities. This article reviews a spectrum of cerebral malformations, their MR imaging features, and the clinical implications of these findings. Additionally, it outlines the growing importance of fetal MR imaging in the context of perinatal care.

Prenatal ultrasound findings of holoprosencephaly spectrum: Unusual associations

OBJECTIVE

The objective of this study is to evaluate the prenatal diagnosis, postnatal characteristics, and the spectrum of associated findings in fetuses with holoprosencephaly (HPE).

METHODS

Fetal neurosonograms, postnatal assessment, and chromosomal analysis were performed in a cohort of 25 fetuses with HPE.

RESULTS

The prevalence of HPE in high-risk pregnancies was 4.4:10 000. The alobar subtype was the most frequently encountered, with 17 cases (68%). Interestingly, among them, four cases (16%) presented with the rare agnathia-otocephaly complex. Chromosomal abnormalities were detected in 11 cases (44%), the most frequent being trisomy 13 in seven cases (five alobar, one semilobar, and one lobar HPE), followed by trisomy 18 in two cases with semilobar HPE. One case of alobar HPE had 45, XX, t(18;22) (q10;q10), -18p karyotyping, and one case of semilobar HPE was associated with triploidy. Facial malformations in HPE spectrum ranged from cyclopia, proboscis, and arrhinia that were associated with the alobar subtype to hypotelorism and median cleft that were frequent among the semilobar and lobar subtypes. Associated neural tube defects were identified in 12% of cases.

CONCLUSION

Our study illustrates the clinical and genetic heterogeneity of HPE and describes different chromosomal abnormalities associated with HPE.

Prenatal diagnosis of holoprosencephaly

Holoprosencephaly is a spectrum of congenital defects of forebrain development characterized by incomplete separation of the cerebral hemispheres. In vivo diagnosis can be established with prenatal brain imaging and disease severity correlates with extent of abnormally developed brain tissue. Advances in magnetic resonance imaging (MRI) over the past 25 years and their application to the fetus have enabled diagnosis of holoprosencephaly in utero. Here, we report on the prenatal diagnosis of holoprosencephaly using MRI as part of a diagnostic and management evaluation at a tertiary and quaternary referral center. Using an advanced MRI protocol and a 1.5-Tesla magnet, we show radiographic data diagnostic for the holoprosencephaly spectrum, including alobar, semilobar, lobar, middle interhemispheric, and septopreoptic variant. Accurate prenatal evaluation is important because the severity of imaging findings correlates with postnatal morbidity and mortality in holoprosencephaly. Therefore, this work has implications for the evaluation, diagnosis, management, and genetic counseling that families can receive during a pregnancy.

Prenatal Diagnosis of Holoprosencephaly With Cyclopia

The authors report a case of holoprosencephaly with cyclopia, diagnosed prenatally at a gestational age of 19 weeks. The patient’s clinical history was normal, except for aspirin usage for her headache. The sonographic diagnosis was based on the intracranial finding of fused thalami with no visible midline structures and facial abnormalities, including cyclopia, proboscis, and absence of the nose. These findings are characteristic of alobar holoprosencephaly. With the informed consent of the patient, the pregnancy was terminated by induction after proper counseling. Postmortem examination of the abortus material confirmed the presence of cyclopia and a proboscis.

Airway management in an infant with alobar holoprosencephaly and cebocephaly associated with maternal diabetes mellitus

We report a case of alobar holoprosencephaly (HPE) and cebocephaly associated with uncontrolled maternal type 1 (insulin-dependent) diabetes mellitus. Alobar HPE is the most severe form of HPE. Patients with cebocephaly have ocular hypotelorism and a proboscis with a single, blind-ended nostril. Shortly after our patient was born, we were consulted for airway management, as the parents' goal was to bring their child home. A tracheostomy tube was placed, and choanal atresia repair was eventually performed. The infant was never decannulated, however, and she died at the age of 9 months of acute respiratory distress syndrome secondary to an upper respiratory infection. To the best of our knowledge, this case represents the longest reported survival of an infant with alobar HPE and cebocephaly. Decisions regarding the care of these infants should be made in a collaborative, multidisciplinary fashion, with special attention paid to the primary caregivers' goals of care.

Prenatal diagnosis of fetal gastroschisis using three-dimensional ultrasound: comparison between the 20th and 21st centuries

OBJECTIVE

In order to compare the trends and improvements of prenatal diagnosis of gastroschisis, we herein retrospectively reviewed our cases of fetal gastroschisis detected by three-dimensional ultrasound (3D US) between the two centuries.

MATERIALS AND METHODS

We reviewed our computer database of prenatal diagnosis on gastroschisis in National Cheng Kung University Hospital from October 1994 to November 2011. All the fetuses were initially scanned by two-dimensional (2D) US to locate the region of interest (ROI). Then, the 3D probe was used to scan all the ROI systematically and mechanically, and all the images were stored on laser discs for further 3D visualization and reconstruction. To compare the characteristics at prenatal diagnosis of gastroschisis between the 20th and 21st centuries in our hospital, the Chi-square test and Student t test were used. The p values less than 0.05 and 0.1 were considered statistically significant.

RESULTS

In total, 26 fetuses with gastroschisis were depicted by 3D US in utero (10 cases were diagnosed in the 20th century and 16 cases in the 21st century). The ranges of gestational age at prenatal diagnosis of gastroschisis by 3D US in the 20th century were between 14 and 34 weeks (mean: 21.6 weeks) and between 14 and 33 weeks (mean: 21.9 weeks) in the 21st century. Moreover, seven cases (70%) were diagnosed before the third trimester in the 20th century, whereas 13 cases (81%) were diagnosed before the third trimester in the 21st century.

CONCLUSION

Although without statistical significance, higher prenatal diagnosis rate before the third trimester in the 21st century was noted. The improvement of 3D US has remarkable advantages in adding novel visual depiction of a 3D lesion of a 3D fetus in 3D US after reconstruction and thus assists substantially in prenatal diagnosis, genetic consultation, and perinatal management of gastroschisis.

Airway Management in an Infant with Alobar Holoprosencephaly and Cebocephaly Associated with Maternal Diabetes Mellitus

We report a case of alobar holoprosencephaly (HPE) and cebocephaly associated with uncontrolled maternal type 1 (insulin-dependent) diabetes mellitus. Alobar HPE is the most severe form of HPE. Patients with cebocephaly have ocular hypotelorism and a proboscis with a single, blind-ended nostril. Shortly after our patient was born, we were consulted for airway management, as the parents’ goal was to bringtheir child home. A tracheostomy tube was placed, and choanal atresia repair was eventually performed. The infant was never decannulated, however, and she died at the age of 9 months of acute respiratory distress syndrome secondary to an upper respiratory infection. To the best of our knowledge, this case represents the longest reported survival of an infant with alobar HPE and cebocephaly. Decisions regarding the care of these infants should be made in a collaborative, multidisciplinary fashion, with special attention paid to the primary caregivers’ goals of care.

Prenatal diagnosis of fetal congenital cystic adenomatoid malformation of the lung using three-dimensional ultrasound: comparison between the 20th and 21st centuries

OBJECTIVE

Congenital cystic adenomatoid malformation of the lung (CCAML) is one of the most common lung lesions diagnosed prenatally. In order to compare the trends and improvements of prenatal diagnosis of CCAML, we herein retrospectively reviewed our cases of fetal CCAML detected by three-dimensional ultrasound (3-D US) between two centuries.

MATERIALS AND METHODS

We reviewed our computer database of prenatal diagnosis of CCAML in National Cheng Kung University Hospital from October 1994 to November 2011. All of the fetuses were initially scanned by two-dimensional (2-D) US to locate the region-of-interest (ROI). Then, the 3-D probe was used to scan all of the ROI systematically and mechanically, and the images were stored in the laser discs for further 3-D visualization and reconstruction. To compare the characteristics at prenatal diagnosis of CCAML between the 20th and 21st centuries in our hospital, Chi-square tests were undertaken. A p value <0.05 was considered as statistically significant.

RESULTS

In total, 58 fetuses with CCAML were depicted by 3-D US in utero (12 cases were diagnosed in the 20th century and 46 cases in the 21st century). The ranges of gestational age at prenatal diagnosis of CCAML by 3-D US in the 20th century were between 15 and 36 weeks (mean=24 weeks), and were between 16 and 31 weeks (mean=22 weeks) in the 21st century. Moreover, nine cases (75%) were diagnosed at the second trimester in the 20th century, whereas 44 cases (96%) were diagnosed at the second trimester in the 21st century.

CONCLUSION

The advancement of 3-D US has remarkable advantages in adding novel visual depiction of a 3-D lesion of a 3-D fetus in 3-D US after reconstruction, and thus assists substantially in the prenatal diagnosis and genetic consultation of CCAML. Furthermore, the trend analysis in this series showed a significantly earlier gestational age at prenatal diagnosis of CCAML in the 21st century than that in the 20th century.

Holoprosencephaly at prenatal diagnosis: analysis of 28 cases regarding etiopathogenic diagnoses

OBJECTIVE

To assess the likelihood of finding an etiopathogenic cause in an ultrasonographic prenatal diagnosis of holoprosencephaly.

MATERIALS AND METHODS

From January 1996 to June 2010, 13 883 prenatal diagnoses through chorionic villus sampling or amniocentesis were made. Every fetus with holoprosencephaly at ultrasound was evaluated. Gestational age, additional ultrasound findings, and fetal karyotype were recorded. Molecular diagnosis and parental karyotype were studied, if relevant.

RESULTS

Twenty-eight fetuses were diagnosed with holoprosencephaly (0.20%). All cases had additional ultrasound findings (100%). A definitive etiology was found in 23 cases (82.14%): karyotype was abnormal in 19 (67.9%) and normal in 8 (28.5%) cases. In the normal karyotype group, although molecular testing was performed in a few cases, one mutation of gene SIX 3 was diagnosed, one diagnosis of dysgnathia complex was made, and two fetuses presented Smith-Lemli-Opitz syndrome. No etiopathogenic diagnosis was made in five fetuses.

CONCLUSIONS

Our results showed that a definitive etiology can be established in most cases of prenatal holoprosencephaly. Chromosomal anomalies were the most frequent finding. However, in euploid fetuses, molecular diagnosis is worthwhile, as different genes with different inheritance patterns may be responsible for this malformation. Thorough evaluation proved beneficial for assessing more accurate prognosis and recurrence risks.

Differential Diagnosis of Intracranial Anomalies

The sonographic differentiation between hydranencephaly, severe hydrocephalus, and holoprosencephaly can be difficult. Careful examination of cranial anatomy has proven quite useful in differentiating these three anomalies. The presence or absence of a complete midline falx, cortical tissue, facial and cardiac anomalies, internal carotid arteries, and fetal circle of Willis is useful in providing accurate diagnoses. This case reports a failure to recognize hydrocephalus despite the presence of well-established identifiers.

Semilobar holoprosencephaly with associated cyclopia and radial aplasia: first trimester diagnosis by means of integrating 2D-3D ultrasound

INTRODUCTION

Holoprosencephaly (HPE) is commonly associated with facial malformations. We present a case of semilobar HPE associated with distal limb defect which was detected at 12 weeks of gestation.

CASE

The fetus had a crown-rump length of 60 mm (12 weeks-4 days), had nuchal translucency thickness of 1.5 mm. Initial two-dimensional (2D) ultrasound revealed the absence of nasal bone, decreased BPD and abnormal profile. Transvaginal 2D ultrasound was effective in the detection of HPE (partially absence of the interhemispheric fissure, fused thalami, the choroid plexuses were not visualized bilateraly: absent 'butterfly' sign), cylopia, absence of the nose and unilateral radial aplasia. Three dimensional (3D) ultrasound provided a better visualization of the associated anomalies. The necropsy result confirmed the sonographic findings: the diagnosis was semilobar HPE, cyclopia, absence of the nose, and the absence of the radius and the thumb in the left arm.

DISCUSSION

Transvaginal 2D sonographic examination is effective in detection of the cases with HPE at first trimester. Fetal morphological study through 3D ultrasound may facilitate the diagnosis of associated anomalies.

Three-dimensional ultrasound in prenatal diagnosis

PURPOSE OF REVIEW

Several technological advances have greatly improved three-dimensional sonography, which have improved acquisition and display capabilities. This review describes these technical changes as well as current applications of 3D sonography in prenatal diagnosis.

RECENT FINDINGS

Recently published papers have emphasized the potential of getting a precise 'any plane of choice' from a three-dimensional volume, as a new way of scanning, based on the off-line analysis of a volume dataset. Surface mode has been used to demonstrate malformations and genetic diseases. The maximum rendering mode, which highlights bones, has great potential for imaging the nasal bones and the frontal bones with the metopic suture. Organ volume can be measured, but the utility of this in clinical practice remains to be determined. Three-dimensional ultrasound needs to be standardized.

SUMMARY

Three-dimensional ultrasonography is the most rapidly developing technique in fetal imaging. New features will permit the transition from the era of 'sonography in two-dimensional planes' to 'volume ultrasound'.

First trimester three-dimensional transvaginal imaging of alobar holoprosencephaly associated with proboscis and hypotelorism (ethmocephaly) in a 46,XX fetus

A 19-year-old woman was scanned at 10(+6) weeks gestation by 2D-3D ultrasound. The fetus had a crown-rump length of 40.9 mm, with the cephalic pole occupied by a single cystic cavity measuring 10.6 x 7.7 x 6.8 mm and severe hypotelorism associated with mid-facial hypoplasia. 3D ultrasound confirmed the malformations seen on the 2D scan and enabled the visualization of a proboscis and a low-set right ear. Fetal karyotyping was performed by chorionic villus sampling. Due to major fetal malformations of the fetus, the patient opted for termination of pregnancy. First trimester sonographic diagnosis of holoprosencephaly relies on bilateral visualization of choroid plexuses in what has been called the 'butterfly' sign. Differential diagnosis between holoprosencephaly and hydranencephaly may be difficult in the first trimester of pregnancy. However, midline structures such as falx cerebri, interhemispheric fissure and third ventricle are present in hydranencephaly and are absent in alobar holoprosencephaly, and thalami are never fused in hydranencephaly. 3D ultrasound has demonstrated an increased definition of anatomical abnormalities of malformations, compared with 2D ultrasound, and has proven to be crucial in the decision-making process of parents and in later prenatal counseling, especially in this case where necroscopy examination was refused by the parents. Images obtained by 3D ultrasound gave detailed insight into this ventral midline anomaly, depicting much of the disordered prosencephalic development.

Objective evaluation of sylvian fissure development by multiplanar 3-dimensional ultrasonography

OBJECTIVE

Evaluation of fetal cerebral cortex sulcation is important for the pre-natal diagnosis of neuronal migration disorders. Although abnormal sylvian fissure morphologic features are frequently observed in these conditions, the diagnosis of an abnormal sylvian fissure relies on subjective interpretation of ultrasonographic images. This study was performed to develop an objective ultrasonographic parameter for sylvian fissure evaluation.

METHODS

This cross-sectional study included 202 normal singleton pregnancies without fetal anomalies. Using multiplanar, 3-dimensional ultrasonography, the sylvian fissure midpoint was identified. The sylvian fissure-to-parietal bone distance (SPB) was measured from the midpoint to the inner surface of the parietal bone, perpendicular to the falx cerebri. Bland-Altman plots were used to determine intraobserver and interobserver agreement. Regression analysis was used to evaluate the correlation between SPB measurements and gestational age.

RESULTS

Two hundred (99%) of 202 pregnancies had a visible sylvian fissure, identifiable as early as 12 weeks of gestation. The mean SPB values at 12 and 41 weeks were 2.1 and 14.3 mm, respectively. Intraobserver and interobserver mean differences between paired measurements were 0.01 mm (95% limits of agreement, -0.41 to 0.43 mm) and 0.05 mm (95% limits of agreement, -1.79 to 1.90 mm), respectively. A linear correlation was observed between the SPB and gestational age (multiple R=0.91; R2=0.82 [SPB = -2.85 + 0.42 x gestational age]).

CONCLUSIONS

(1) The SPB can be reproducibly measured from 12 weeks of gestation to term; and (2) a strong positive correlation was observed between the SPB and gestational age.

Prenatal diagnosis of holoprosencephaly with ethmocephaly via 3-dimensional sonography

We present the prenatal 3-dimensional (3D) sonographic findings in a case of holoprosencephaly with ethmocephaly at 32 weeks' gestation. The sonographic diagnosis was based on the intracranial findings of a single ventricle and bulb-shaped appearance of the thalami and facial abnormalities, including hypotelorism with proboscis. Chromosome study of the fetus revealed a normal female karyotype (46,XX). Postmortem examination confirmed the 3D sonographic findings. This case demonstrates that the use of 3D sonography improves the imaging and the understanding of the condition of the intracranial abnormalities and the facial anomalies.

Three- and 4-dimensional ultrasound in obstetric practice: does it help?

OBJECTIVE

The purpose of this article was to review the published literature on 3-dimensional ultrasound (3DUS) and 4-dimensional ultrasound (4DUS) in obstetrics and determine whether 3DUS adds diagnostic information to what is currently provided by 2-dimensional ultrasound (2DUS) and, if so, in what areas.

METHODS

A PubMed search was conducted for articles reporting on the use of 3DUS or 4DUS in obstetrics. Seven-hundred six articles were identified, and among those, 525 were actually related to the subject of this review. Articles describing technical developments, clinical studies, reviews, editorials, and studies on fetal behavior or maternal-fetal bonding were reviewed.

RESULTS

Three-dimensional ultrasound provides additional diagnostic information for the diagnosis of facial anomalies, especially facial clefts. There is also evidence that 3DUS provides additional diagnostic information in neural tube defects and skeletal malformations. Large studies comparing 2DUS and 3DUS for the diagnosis of congenital anomalies have not provided conclusive results. Preliminary evidence suggests that sonographic tomography may decrease the examination time of the obstetric ultrasound examination, with minimal impact on the visualization rates of anatomic structures.

CONCLUSIONS

Three-dimensional ultrasound provides additional diagnostic information for the diagnosis of facial anomalies, evaluation of neural tube defects, and skeletal malformations. Additional research is needed to determine the clinical role of 3DUS and 4DUS for the diagnosis of congenital heart disease and central nervous system anomalies. Future studies should determine whether the information contained in the volume data set, by itself, is sufficient to evaluate fetal biometric measurements and diagnose congenital anomalies.

A case of holoprosencephaly and cebocephaly associated to torch infection

Cebocephaly is a very rare congenital anomaly combining a severe midline facial malformation and holoprosencephaly. Here we report on first case of cebocephaly with semilobar holoprosencephaly, hypotelorism, and a single nostril due to intrauterine TORCH infection (Toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], Rubella, Cytomegalovirus [CMV], and Herpes infections) in the English language literature. Chromosomal analysis showed normal karyotyping.

Prenatal three-dimensional/four-dimensional sonographic demonstration of facial dysmorphisms associated with holoprosencephaly

In this report, we describe the prenatal use of 3-dimensional 4-dimensional (3D/4D) sonography to visualize the facial dysmorphisms associated with holoprosencephaly in 6 fetuses (2 with cyclopia, 1 with cebocephaly, and 3 with holoprosencephaly-premaxillary agenesis). Ultrafast MRI was also used. The 3D/4D sonographic images allowed easy, rapid, and precise prenatal evaluation of the facial dysmorphisms associated with holoprosencephaly; the MRI scans provided little additional information. The 3D/4D sonograms helped the parents visualize the abnormalities and facilitated their acceptance of perinatal genetic counseling.

Prenatal diagnosis of fetal acrania using three-dimensional ultrasound

Fetal acrania is uniformly lethal and termination is suggested whenever the diagnosis is made. Traditionally, the diagnostic tool was 2-D ultrasound (US). In this series, we report our work of detecting acrania using 3-D US. We reviewed our medical records of prenatal diagnosis on fetal acrania in National Cheng Kung University Hospital from May 1997 to December 2002. All the cases were scanned by a 3-D US scanner. In total, 29 cases of fetal acrania were diagnosed. The range of gestational age at prenatal diagnosis by US was between 11 and 21 weeks and 44% were depicted in the first trimester. Among them, 93.1% were isolated findings, and one was associated with trisomy 18. Comparing with previous literature, 3-D US can detect fetal acrania as early as 2-D US, and it also can provide additional vivid illustration after various modes of reconstruction, which 2-D US cannot. In conclusion, 3-D US may contribute to early detection of fetal acrania and provide a novel visual depiction of this defect after reconstruction; thus, assists substantially in diagnosis as well as consultation.

Three-dimensional power Doppler ultrasound for the assessment of the fetal brain blood flow in normal gestation

Early identification of the abnormal fetal brain vascularization and blood flow is very important, because the deficient perfusion of the fetal brain may be related to a poor prognosis of the central nervous system (CNS) development. To assess the fetal brain vascularization and the blood flow in normal gestation, we measured the fetal brain vascularization and the brain blood flow in normal fetuses using three-dimensional (3-D) power Doppler ultrasound (US) and the quantitative 3-D power Doppler histogram analysis. This study was undertaken by a prospective and cross-sectional design. In total, 155 normal singletons with gestational age (GA) between 21 and 40 weeks were included. The 3-D power Doppler US and the quantitative 3-D histogram analyses were used to assess the fetal brain vascular indexes, i.e., vascularization index (VI), flow index (FI) and vascularization-flow index (VFI), in each case. Our results revealed that all the fetal brain VI, FI and VFI increased significantly with GA (all p<0.001). In addition, the fetal brain VI, FI and VFI were all significantly correlated with the common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight. Our study indicates that fetal brain vascularization and blood flow increase significantly with the advancement of GA as well as the fetal common growth indices during normal gestation. We believe our data may serve as a reference for further studies of the fetal brain blood flow in abnormal conditions.

Quantification of ovarian stromal Doppler signals in postmenopausal women receiving hormone replacement therapy

OBJECTIVE

To investigate the effect of continuous-combined hormone replacement therapy (HRT) on ovarian circulation, we used three-dimensional power Doppler ultrasound to assess ovarian stromal blood flow in postmenopausal women.

DESIGN

Forty healthy, postmenopausal women were enrolled in this prospective, controlled study. They were divided into two groups: the control group (20 patients with no HRT treatment) and the HRT group [initially 20 patients, but later 15 patients who completed the study, using continuous-combined conjugated equine estrogen (0.625 mg/day) plus medroxyprogesterone (5 mg/day)]. All patients underwent transvaginal three-dimensional power Doppler ultrasonography at the time of recruitment and 3 months later. The ovarian stromal flow indices, including vascularization-flow index (VFI), flow index (FI), and vascularization index (VI), were measured. Blood withdrawals for serum follicle-stimulating hormone and estrogen level testing were obtained before and after 3 months of treatment.

RESULTS

All the variables in the hormone profile showed significant difference (P < 0.05) after 3 months of treatment in the HRT group. Of interest, the three-dimensional power Doppler indices of ovarian stromal flow, VFI (0.13 +/- 0.11 --> 0.59 +/- 0.49), FI (30.47 +/- 12.06 --> 38.41 +/- 10.21), and VI (0.31 +/- 0.27 --> 1.12 +/- 0.95) all showed significant increase (P < 0.05) after 3 months of HRT treatment.

CONCLUSIONS

There was a significant increase in ovarian stromal flow indices after 3 months of treatment in the HRT group, but not in the controls. Monitoring the ovarian flow changes by three-dimensional power Doppler may be of clinical importance when HRT is given.

Quantitative three-dimensional power Doppler sonography for assessment of the fetal renal blood flow in normal gestation

Renal blood flow is very important to fetal hemodynamics. To assess the development of fetal renal vascularization and blood flow in normal gestation, we measured the fetal renal vascularization and blood flow in healthy fetuses using three-dimensional (3-D) power Doppler sonography and quantitative 3-D power Doppler histogram analysis. This study was undertaken with a prospective, cross-sectional design. In total, 106 healthy singletons with gestational ages between 20 and 40 weeks were included. The 3-D power Doppler sonography and quantitative histogram analyses were used to assess the fetal renal vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) in each case. Our results showed that all the VI, FI and VFI increased significantly with gestational age (GA). Using GA as the independent variable, the linear regression equations for fetal renal VI, FI and VFI were VI = 0.214 x GA - 3.5289 (r = 0.84, n = 106, p < 0.0001); FI = 0.3326 x GA + 35.224 (r = 0.33, n = 106, p < 0.001); and VFI = 0.1047 x GA - 1.8064 (r = 0.82, n = 106, p < 0.0001). Our study indicates that normal fetal renal vasculature and blood flow increase with the advancement of gestational age. In addition to our previous study for fetal renal volume using 3-D sonography, our data in this series may serve as a reference for further studies of fetal renal blood flow in abnormal conditions.

Assessment of normal fetal liver blood flow using quantitative three-dimensional power Doppler ultrasound

Fetal liver blood flow is very important for fetal hemodynamics. To assess the development of fetal liver vascularization and blood flow in normal gestation, we measured the fetal liver vascularization and blood flow in normal fetuses using the three-dimensional (3-D) power Doppler ultrasound (US) and quantitative 3-D power Doppler histogram analysis. This study was undertaken with a prospective, cross-sectional design. In total, 196 normal singletons with gestational age between 20 and 40 weeks were included. The 3-D power Doppler US and the quantitative histogram analysis were used to assess the fetal liver vascularization index (VI), flow index (FI), vascularization-flow index (VFI) and mean greyness in each case. Our results showed that all the fetal liver VI, FI and VFI increased significantly with gestational age (GA), whereas, fetal liver mean greyness decreased with GA. Using GA as the independent variable, the linear regression equations for fetal liver VI, FI, VFI and mean greyness were VI = 0.5746 x GA - 5.8264 (r = 0.86, p < 0.0001), FI = 0.3291 x GA + 35.624 (r = 0.35, p < 0.001), VFI = 0.2905 x GA - 3.4871 (r = 0.82, p < 0.0001) and mean greyness = -0.2034 x GA + 42.315 (r = -0.20, p < 0.0001). In addition, fetal liver VI, FI, VFI and nean greyness were all significantly correlated with common fetal growth indexes, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight. Our study indicates that normal fetal liver vascularization and blood flow change significantly with the advancement of GA as well as fetal growth indexes. We believe our data may serve as a reference for further studies of fetal liver blood flow in abnormal conditions.

Outcome of children with prenatally diagnosed central nervous system malformations

OBJECTIVE

To study the outcome of pregnancies with a prenatally diagnosed central nervous system (CNS) malformation.

METHODS

Leiden University Medical Centre is a tertiary referral center for fetal ultrasound and invasive prenatal diagnosis. Maternal and neonatal records of prenatally diagnosed CNS malformations were retrospectively reviewed over a 6-year period (1993-1998). Information on current development of surviving children was obtained by contacting the care-giving pediatric neurologist.

RESULTS

During the study period 124 fetuses were diagnosed with a CNS malformation. Data on pregnancy and delivery were available for 118 pregnancies. Additional malformations were present in 47% of fetuses (55/118). A total of 46% of pregnancies (54/118) were terminated, and 15% (18/118) ended in spontaneous intrauterine death. A total of 39% of pregnancies (46/118) resulted in live birth, and 29 of the infants were still alive at the age of 3 months. One child was lost to follow-up, one infant died at the age of 4 months, and two children died at the age of 3 years. Psychomotor development of the remaining 25 children was normal for five, slightly disabled for seven, moderately disabled for five and severely disabled for eight.

CONCLUSION

Due to the high rate of termination of pregnancy and to the frequent association with other anomalies, the survival rate of pregnancies in which a CNS defect had been diagnosed prenatally was only 25%. More than 50% of surviving children were moderately or severely disabled.

Assessment of placental fractional moving blood volume using quantitative three-dimensional power doppler ultrasound

To test the hypothesis that the placental fractional moving blood volume is different with advancing gestational age (GA), we assessed the vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) of the placenta in normal pregnancy by using three-dimensional (3-D) power Doppler ultrasound (US). We enrolled 100 healthy pregnant women with gestational age between 20 to 40 weeks for this study. Three-dimensional power Doppler ultrasonography was used to assess the VI, FI and VFI in each case. Our results showed that the linear regression equations for VI, FI and VFI, by using GA as the independent variable, were VI = 0.27107 x GA -4.02748 (r = 0.84, p < 0.0001), FI = 0.56115 x GA + 34.28945 (r = 0.49, p < 0.001), and VFI = 0.15663 x GA -2.53810 (r = 0.82, p < 0.0001), respectively. In addition, the VI, FI and VFI values of the placental flow were also positively correlated with the fetal growth indices, namely, biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference and estimated fetal weight (all p values < 0.001). In conclusion, our study illustrates that the fractional moving blood volume of the placenta is positively correlated with the increment of gestational age and the fetal growth indices. Our data may be used as a reference in the assessment of the placental fractional moving blood volume using the quantitative 3-D power Doppler US.

Assessment of fetal adrenal gland volume using three-dimensional ultrasound

To assess the normal fetal adrenal gland volume during normal gestation, we performed a prospective study on 119 normal fetuses with gestational age ranging from 21 to 40 weeks using a 3-D ultrasound (US) volume scanner with a pure cross-sectional design. Polynomial regression analysis was calculated to find the best-fit model between gestational age (GA) and adrenal gland volume. In addition, estimated fetal weight (EFW) was also measured to demonstrate the correlation between adrenal gland volume and fetal weight. Our results showed that fetal adrenal gland volume is highly correlated with GA. Furthermore, using GA as the independent variable and adrenal gland volume as the dependent variable, the best-fit regression equation was adrenal glands volume (mL) = -0.2683 x GA + 0.0082 x GA(2) + 3.1927 (r = 0.93, n = 119, p < 0.0001). For clinical use, a chart of normal growth centiles of fetal adrenal gland volume in utero was then calculated based on this equation. In addition, fetal adrenal gland volume during normal gestation is also highly correlated with EFW (p < 0.0001). In conclusion, our data of fetal adrenal gland volume assessed by 3-D US can serve as a useful reference in evaluating fetal growth status during gestation.

Prenatal diagnosis of fetal multicystic dysplastic kidney with two-dimensional and three-dimensional ultrasound

Fetal multicystic dysplastic kidney (MCDK) may have grave prognosis and prenatal diagnosis of MCDK by ultrasound (US) is very important. Traditionally, MCDK is diagnosed by 2-D US. Recently, 3-D US has emerged, and may overcome the weakness of 2-D US. In this series, we retrospectively analysed the cases of MCDK diagnosed by prenatal 2-D and 3-D US from November 1995 to March 2002 to evaluate the prenatal sonographic characteristics of this disease and to compare the efficacy of 2-D and 3-D US. The 2-D assessment included the lesion of MCDK, the amniotic fluid volume and associated anomalies. The 3-D assessment included three-orthogonal multiplanar views and various rendering modes of reconstruction of MCDK. In total, 28 cases were diagnosed by prenatal 2-D and 3-D US. Within the study period, 2-D US detected 100% of MCDK, as did 3-D US, and revealed that left, right and bilateral MCDK were in 46.4%, 28.6%, and 25% of cases, respectively. Oligohydromnios was present in 6 cases (21.4%). In addition, 3-D US showed fetal MCDK vividly and provided a whole view of the disease that assisted comprehension of the severity and extent better than 2-D US. In conclusion, although 2-D US detected all the cases of fetal MCDK in utero as did 3-D US, the 3-D images generated by various rendering modes can further assist in evaluating the severity and extent of MCDK, with a novel view that substantially aids the medical team in prenatal management and the parents in genetic consultation.

Prenatal depiction of cystic hygroma using three-dimensional ultrasound

Prenatal diagnosis of fetal cystic hygroma is very important in clinical medicine. In this series, we report our work of detecting cystic hygroma using three-dimensional (3-D) ultrasound (US). We reviewed our computer database of prenatal diagnosis on cystic hygroma in National Cheng Kung University Hospital from May 1995 to June 2000. All the fetuses were initially scanned by a high-resolution, real-time, 2-D US scanner and subsequently by a 3-D US scanner. In total, 23 cases of fetal cystic hygroma were diagnosed in utero. The range of gestational age at prenatal diagnosis by US was between 11 and 24 weeks, and 91% were diagnosed before 21 weeks. Among them, 8 cases (35%) were Turner syndrome (45,X), and 10 cases (43%) were complicated with hydrops fetalis. Although the diagnostic rates by 2-D US and 3-D US were both 100% (23 of 23), notably, 3-D US can provide additional vivid illustrations in 3-D after various modes of reconstruction, but 2-D US cannot. In conclusion, 3-D US may add novel visual depiction of the lesion in 3-D after reconstruction and, thus, assists substantially in prenatal consultation.

Ovarian stroma flow intensity decreases by age: a three-dimensional power doppler ultrasonographic study

This was a prospective comparative clinical study to test the hypothesis that the flow intensity of the ovarian stroma decreases in the order of the aging process. A total of 100 consecutive women who came to our outpatient clinic for Pap smear examination were recruited. They were divided into three groups. The premenopause group (58 women) had menstruated within the last 3 months and had normal ovaries (no polycystic ovary or any pathologic cyst or mass), as demonstrated on the baseline ultrasound (US) examination. The perimenopause group (20 women) had last menstruated between 3 and 12 months earlier and had normal ovaries. The postmenopause group (22 women) had had no menstrual cycle within the last 12 months and had normal ovaries. Three-dimensional power Doppler US was applied to quantify the blood flow and vascularization within the stroma of the bilateral ovaries. The results showed that the E2 level decreased in the order of: premenopause (mean +/- SD; 40.88 +/- 40.65 pg/mL), perimenopause (22.00 +/- 13.61 pg/mL), then postmenopause (17.25 +/- 16.40 pg/mL). The vascularization index (VI) (6.95 +/- 8.35; 1.11 +/- 0.93; 0.53 +/- 1.75; respectively), flow index (FI) (15.98 +/- 7.59; 12.00 +/- 3.86; 5.18 +/- 5.31; respectively) and vascularization-flow index (VFI) (1.25 +/- 1.59; 0.18 +/- 0.15; 0.09 +/- 0.32; respectively) all decreased significantly in the order of premenopause, perimenopause, then postmenopause. To the best of our knowledge, this is the first study using 3-D power Doppler sonography that proves that the flow intensity decreases along with the aging process in the ovarian stroma.

Assessment of fetal anatomy in the first trimester using two- and three-dimensional ultrasound

The objective of this study was to perform a complete anatomical survey of the fetus at 12-13 weeks gestation using stored volumes acquired by a three-dimensional (3D) scanner. 159 consecutive women at 12-13 weeks gestation who had a routine early pregnancy scan in our unit were recruited. A complete survey of the fetal anatomy was attempted by two-dimensional (2D) transabdominal and, if needed, transvaginal ultrasound. Then, using a 3D transvaginal probe, two volumes of the whole fetus were acquired. A complete anatomical survey (excluding anatomy of the heart) was attempted using the stored data. A complete anatomical survey was achieved in 93.7% (149) of cases with 2D ultrasound compared to 80.5% (128) of cases with 3D volume acquisition (p<0.001). The nuchal translucency was measured with 2D scanning in 98.7% of cases and in 91.8% of cases using 3D volumes. The mean time to perform a 2D scan was 12.2 min standard deviation (SD 3.4 min) while the mean time to obtain and examine the stored volumes was 8.4 min (SD 1.45 min, p<0.001). Real-time 2D ultrasound is still the best way to examine fetal anatomy in the first trimester. However, 3D ultrasound can be a useful addition to clinical practice, providing views not easily obtained by conventional 2D ultrasound. It can potentially minimize actual scanning time and provides an excellent way to store scanned data.

Prenatal diagnosis of cleft palate by three-dimensional ultrasound

Prenatal diagnosis of cleft palate is very important to prenatal consultation and management after birth. To examine if three-dimensional (3-D) ultrasound (US) is an accurate diagnostic method for clinical use, we analyzed our experience in detecting cleft palate by 3-D US. From June 1996 to January 2000, 21 fetuses with facial clefts were scanned by 2-D US, as well as by 3-D US. The coronal and oblique planes were reconstructed by 3-D US to detect the cleft palate. In addition, level II US was performed to find any possibly associated anomalies. All the scans were recorded on optic disks for final analysis. In our study, the gestational age when prenatal diagnosis was made by US initially was between 20 and 34 weeks. The accuracy for prenatal diagnosis of cleft lip with or without cleft palate by 3-D US was 100%, which was superior to that by 2-D US (p < 0.05). In addition, we proposed a novel method to evaluate the cleft palate systemically by 3-D US. In conclusion, from our study, fetuses with cleft lip combined with or without cleft palate can be easily differentiated by 3-D US. The reconstruction of coronal and oblique planes by 3-D US is a powerful tool for detecting cleft palate.

The role of three-dimensional ultrasound in obstetrics

Three-dimensional ultrasound is a relatively new imaging modality with several potential advantages over conventional two-dimensional sonography. There is now increasing evidence that three-dimensional ultrasound can in many ways assist in the examination of the fetus. The enthusiasm generated by some groups, however, is not universally shared. It is the aim of this review to summarize the contemporary role of three-dimensional ultrasound in obstetric sonography by giving a critical appraisal of the relevant literature published recently, with emphasis on first and second trimester anatomy and fetal organ and placenta volumetry.

Three-dimensional ultrasonography in early pregnancy

Three-dimensional ultrasound was introduced into clinical use over a decade ago. Early attempts on three-dimensional ultrasound were primitive and limited to experimental use only. Recently, it was used as a powerful tool to display three-dimensional fetal appearance and assess normal and pathological conditions. Because of the improvement in image resolution and reconstruction speed, three-dimensional ultrasound is now more and more popular in many centers, and used commonly as an adjunct in prenatal diagnosis. Indeed, a skillful sonographer may usually make the correct diagnosis of fetal anomaly with simply two-dimensional ultrasound. Nonetheless, the situation is gradually changing, because some anomalies have been diagnosed only based on the findings of three-dimensional ultrasound. In spite of that, the application of three-dimensional ultrasound is still less discussed in early pregnancy. In this article, the authors clarify the capability of three-dimensional ultrasound in different anatomic areas, and catalog its clinical merits in the early pregnancy to date. We also present the safety guidelines for its use in the first trimester.