Callosal dysgenesis in fetuses with ventriculomegaly: levels of agreement between imaging modalities and postnatal outcome

OBJECTIVE

To assess neurodevelopmental outcome of fetuses diagnosed with callosal abnormalities after referral for ventriculomegaly.

METHODS

This sub-analysis of a prospective study of 430 fetuses, which were referred for ventriculomegaly and underwent sonography and magnetic resonance imaging (MRI), included those fetuses with a diagnosis of corpus callosal abnormalities after recruitment into the main study. Between three and six radiologists independently reviewed ultrasound and MR images and recorded central nervous system (CNS) abnormalities, with final diagnoses being decided by consensus. Postnatal outcomes of fetuses with callosal abnormalities were compared between those with and those without other abnormalities.

RESULTS

Callosal abnormalities were detected in 13% (58/430) of the fetuses referred with ventriculomegaly. Callosal dysgenesis was isolated in 24% (14/58) of these cases, with the remainder complicated by CNS, karyotypic or other major abnormalities. Five fetuses diagnosed prenatally as having isolated callosal abnormalities had additional CNS findings on postnatal assessment. Preconference kappa for callosal abnormalities was 0.76 for ultrasound and 0.78 for MRI, indicating that these investigations had a similar level of operator dependence. Neurodevelopmental outcome was normal or showed only mild delay that resolved in 67% (8/12) children with isolated callosal abnormalities compared to 7% (2/27) in those with non-isolated callosal abnormalities (P = 0.003).

CONCLUSION

Callosal abnormalities are present in a significant proportion of fetuses with a diagnosis of ventriculomegaly. Isolated callosal abnormalities are associated with normal neurodevelopmental outcome in approximately two-thirds of fetuses.

Altered fetal cerebral and cerebellar development in twin-twin transfusion syndrome

BACKGROUND AND PURPOSE

Neurodevelopmental disability is common in twins with TTTS in utero; however, the responsible neuropathology remains uncertain. We proposed to document the frequency of brain abnormalities on clinical fetal MR images and to determine if quantitative fetal brain biometric analysis in twin fetuses with TTTS was different from those in healthy control fetuses.

MATERIALS AND METHODS

We reviewed the fetal brain MR images of 33 twin pairs with TTTS clinically evaluated in our institution. Eighteen fetal MR images of "healthy" twins with TTTS were further studied with biometric analysis in comparison with GA-matched singleton fetuses to detect quantitative differences in brain growth and development.

RESULTS

A higher incidence of anomalies (11/33, 33.3%) was found than previously reported. The most frequent abnormality was ventriculomegaly (7/11, 63%) in both donor and recipient. In "healthy" twins with TTTS, biometric analysis revealed persistently small measurements (cBTD, CMT, TCD, and VAPD) in the donor cerebrum and cerebellum in comparison with their recipient cotwin and healthy control fetuses. These differences were preserved when normalized by cBTD.

CONCLUSIONS

Our findings show that significant brain abnormalities are common in TTTS. In addition, diffuse subtle abnormalities are also present in normal-appearing donor fetal brains that cannot be solely explained by overall growth restriction. Such subtle fetal brain anomalies may explain the high incidence of poor long-term neurodevelopmental outcomes of survivors, and they need to be further investigated with more sophisticated quantitative fetal imaging methodologies.

Frequency and cause of disagreements in imaging diagnosis in children with ventriculomegaly diagnosed prenatally

OBJECTIVES

To assess the frequency and cause of variability in diagnosis on cranial sonography and magnetic resonance imaging (MRI) in children referred following prenatal diagnosis of ventriculomegaly.

METHODS

Between 19 September 2003 and 16 March 2007, 119 infants with ultrasound and/or MRI studies performed within 13 months (median, 6 days) after birth, following prenatal referral for ventriculomegaly, were studied prospectively. There were 97 infants with ultrasound results and 53 with MRI, including 31 with both. Three sonologists and three pediatric neuroradiologists interpreted the postnatal ultrasound and MRI findings, blinded to prenatal diagnosis, and a final consensus diagnosis or group of diagnoses was obtained. Ventricular sizes as well as types of and reasons for any disagreement in diagnosis were recorded. Disagreements on a per patient basis were categorized as being major when they crossed diagnostic categories and had the potential to change patient counseling. Postnatal and prenatal diagnoses were compared.

RESULTS

There was prospective agreement on 42/97 (43%) ultrasound and on 9/53 (17%) MRI readings. Prospective consensus was more likely when the number of central nervous system (CNS) anomalies was lower (P < 0.001 and P = 0.002 for ultrasound and MRI, respectively). In 24/55 (44%) ultrasound and 11/44 (25%) MRI examinations with disagreement in diagnosis, there was disagreement concerning the presence of ventriculomegaly. In 22/97 (23%) ultrasound studies and 22/53 (42%) MRI studies the disagreements were potentially important. Reasons for discrepancies in the reporting of major findings included errors of observation as well as modality differences in depiction of abnormalities. In comparing prenatal with postnatal diagnoses, there were 11/97 (11%) ultrasound and 27/53 (51%) MRI examinations with newly detected major findings, the most common being migrational abnormalities, callosal dysgenesis/destruction and interval development of hemorrhage.

CONCLUSION

Variability in postnatal CNS diagnosis is common after a prenatal diagnosis of ventriculomegaly. This is due in part to a lack of standardization in the definition of postnatal ventriculomegaly.

Fetal MR imaging evidence of prolonged apparent diffusion coefficient decrease in fetal death

We report 2 fetal MR imaging cases at 22 wkGA with cerebral bright DWI and low ADC, 8 and 19 days after documented fetal death. These observations illustrate that decreased diffusion can be present weeks after injury onset, and its presence cannot be used to time injury onset within 1 week, which could significantly impact determination of the proximate cause of fetal brain injury in future cases.

Neurodevelopmental outcome of fetuses referred for ventriculomegaly

OBJECTIVE

To characterize the delivery and postnatal neurodevelopmental outcomes of fetuses referred for ventriculomegaly (VM).

METHODS

Under an internal review board-approved protocol, pregnant women were referred for magnetic resonance imaging (MRI) after sonographic diagnosis of VM and classified into one of four diagnostic groups: Group 1, normal central nervous system (CNS); Group 2, isolated mild VM (10-12 mm); Group 3, isolated VM > 12 mm; and Group 4, other CNS findings. Pregnancy outcome was obtained. Follow-up visits were offered with assessment of neurodevelopmental, adaptive and neurological functioning at 6 months and 1 year and/or 2 years of age. Atrial diameter and VM group differences in developmental outcomes were evaluated using repeated measures logistic regression and Fishers exact test, respectively.

RESULTS

Of 314 fetuses, 253 (81%) were liveborn and survived the neonatal period. Fetuses in Groups 4 and 3 were less likely to progress to live delivery and to survive the neonatal period (60% and 84%, respectively) than were those in Groups 2 or 1 (93% and 100%, respectively, P < 0.001). Of the 143 fetuses followed postnatally, between 41% and 61% had a Bayley Scales of Infant Development (BSID-II) psychomotor developmental index score in the delayed range (< 85) at the follow-up visits, whereas the BSID-II mental developmental index and Vineland Adaptive Behavior composite scores were generally in line with normative expectations. Among those that were liveborn, neither VM group nor prenatal atrial diameter was related to postnatal developmental outcome.

CONCLUSIONS

Diagnostic category and degree of fetal VM based on ultrasound and MRI measurements are associated with the incidence of live births and thus abnormal outcome. Among those undergoing formal postnatal testing, VM grade is not associated with postnatal developmental outcome, but motor functioning is more delayed than is cognitive or adaptive functioning.

Cleft of the secondary palate without cleft lip diagnosed with three-dimensional ultrasound and magnetic resonance imaging in a fetus with Fryns' syndrome

We present a case of Fryns' syndrome diagnosed prenatally using three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). A cleft of the soft palate was diagnosed using 3D thick-slice ultrasonography. Other sonographic findings included a right diaphragmatic hernia, enlarged echogenic kidneys and severe polyhydramnios. The detection of the cleft palate was instrumental in suggesting the diagnosis of Fryns' syndrome in a fetus which also had a diaphragmatic hernia. These findings were also demonstrated with prenatal MRI. The technique of imaging the soft palate en face using a thick-slice technique is presented.

Cystic neuroblastoma: emphasis on gene expression, morphology, and pathogenesis

Cystic neuroblastoma (CN) is an unusual variant of neuroblastoma characterized by a grossly visible cyst(s) and almost always distinctive microcysts on light microscopy. Rarely, CN will appear solid grossly, but microcystification will be present. We examined the clinical, pathologic, and biologic features of 17 cases of CN. The majority of CN had been detected by prenatal ultrasound. The tumors were favorable stage, stroma-poor, but with low or intermediate mitotic-karyorhectic indices and had favorable biologic markers reflected by aneuploidy and by an absence of N-myc amplification and chromosome 1p deletions. However, the high trk expression typically identified in good risk tumors was absent. Although the complete natural history of CN is not fully defined, our experience suggests that some tumors progress in size, whereas others may spontaneously regress or mature. The clinical outcome is excellent, as is expected in localized and stage 4S neuroblastoma in infancy.

Emergency obstetric and gynecologic ultrasound

In conclusion, sonography plays a central role in imaging the obstetric and gynecologic emergencies of babies, girls, and adolescents. Transabdominal and transvaginal sonography each have their respective and combined strengths, which depend on the age, size, anatomy, and social and clinical situation of the patient to be imaged. With recent advances in sonographic technology, especially in the current use of higher-frequency transducers and the promise of three-dimensional imaging, we are undoubtedly seeing more anatomy and pathology, and seeing it more clearly. In the sexually mature patient, transvaginal sonography provides an exceptional view of the normal uterus and adnexae and the myriad presentations of pelvic pathology. This article has reviewed the sonographic techniques that can be used in imaging the pediatric and adolescent pelvis, and has emphasized some of the many pathologic conditions that can be elucidated by pelvic sonography.

Fetal lung masses: prenatal course and outcome

We describe 25 cases of echogenic or complex fetal lung masses seen sonographically and suspected of being cystic adenomatoid malformations or sequestrations of the lung. On the basis of prenatal sonographic appearance, 40% of fetuses were suspected of having type 1, 20% type 2, and 40% type 3 cystic adenomatoid malformations or sequestrations. Sixteen (64%) of the 25 fetuses with lung masses survived the perinatal period, and 80% of the nonaborted fetuses survived. Eleven infants (69% of liveborns) had no respiratory symptoms at birth. Nine of the survivors underwent surgical resections of their masses after birth, whereas the other seven children are being followed conservatively. The postnatal diagnoses revealed that four of the fetuses had sequestrations, one had a sequestration with elements consistent with cystic adenomatoid malformation, and two who were thought to have type 1 cystic adenomatoid malformation had an esophageal duplication cyst and a thoracic neuroblastoma, respectively. All the other infants who had a pathologic diagnosis or postnatal imaging had cystic adenomatoid malformations. Increasing mediastinal shift was associated with decreasing survival as 90% of fetuses with no mediastinal shift are alive, whereas 50% of the nonaborted fetuses with a severe mediastinal shift survived. Follow-up scans in utero were available in 15 cases. The size of the mass became smaller in 53% during gestation. Seventy-one percent of pregnancies had normal amniotic fluid volumes and 29% were complicated by polyhydramnios. Survival of nonaborted fetuses was 100% in pregnancies with normal amniotic fluid compared with 50% in those with polyhydramnios. Eight percent of the fetuses with chest masses had additional structural abnormalities and were karyotypically abnormal. In conclusion, many fetuses with lung masses show improvement of the sonographic findings in utero, and many infants may not be symptomatic at birth. Of the survivors in this series, only slightly greater than half underwent surgery.

Prenatally diagnosed bilateral hyperechoic kidneys with normal amniotic fluid: postnatal outcome

We evaluated a subset of infants with bilateral markedly hyperechoic "bright" kidneys noted prenatally in association with normal amniotic fluid volume during gestation. Prenatal ultrasound showed increased renal parenchymal echogenicity bilaterally with preservation of the medullary pyramid architecture. These children were followed for up to 3 years to determine potential changes in the sonographic appearance of the echogenic renal parenchyma and to assess renal function. In 3 years 8 cases of bilateral hyperechoic fetal kidneys were identified. During postnatal followup renal echogenicity resolved in 4 cases, diminished in 1 and remained the same in 3. The serum creatinine and electrolytes were normal in all cases followed for more than 3 months. Other renal findings included vesicoureteral reflux in 2 of 7 cases, mild pelvic ectasia in 1 and tiny medullary calcifications in 1. The specific etiology of increased echogenicity is unknown, although 1 infant appeared to have a form of autosomal recessive disease with liver hyperechogenicity as well. We conclude that fetuses with bilateral hyperechoic kidneys associated with normal amniotic fluid volume have a favorable outcome. Ultrasonographic finding of marked parenchymal hyperechogenicity appears to improve with time; in our experience renal function is normal and the infants thrive. Continued followup is necessary to determine the long-term natural history of this phenomenon, as is subsequent prenatal and postnatal evaluation of future siblings to assess genetic risk.

Closure of the cerebellar vermis: evaluation with second trimester US

PURPOSE

To evaluate with sonography the normal development of the fetal cerebellum in the second trimester.

MATERIALS AND METHODS

The study included all patients undergoing second trimester genetic amniocentesis who had structurally normal fetuses, in whom the posterior fossa was adequately seen and in whom the karyotype was later determined to be normal. Views of the cerebellum were obtained prospectively, and the inferior vermis was determined to be open or closed at the time of the initial scan. Follow-up was obtained by means of subsequent scans and review of the pediatric record.

RESULTS

Of 897 fetuses that met the inclusion criteria, 147 had an open vermis at initial scanning. At 14 weeks gestation, 56% of fetuses had an open vermis, decreasing to 23% at 15 weeks and 6% at 17 weeks. In utero follow-up sonograms were obtained in 79% of fetuses with an initially open vermis and demonstrated closure in all but one fetus. The remaining 21%, without sonographic follow-up, were normal as newborns.

CONCLUSION

The prenatal diagnosis of Dandy-Walker variant should not be made before 18 weeks gestation because the development of the cerebellar vermis may be incomplete at that time.

Second trimester prenatal findings in duodenal and esophageal atresia without tracheoesophageal fistula

The combination of duodenal atresia and esophageal atresia without tracheoesophageal fistula leads to a closed loop of bowel involving the distal esophagus, stomach, and duodenum. Prenatally, this association of anomalies is visualized as a characteristic dilated C-shaped fluid collection in the fetal abdomen. We report three cases of the association of duodenal and esophageal atresia without tracheoesophageal fistula, identified sonographically in the second trimester of pregnancy.

Is fetal hyperechoic bowel on second-trimester sonogram an indication for amniocentesis?

OBJECTIVE

To determine the clinical significance of hyperechoic bowel seen sonographically in second-trimester fetuses.

METHODS

Fifty fetuses (0.6%) with echogenic bowel were identified sonographically from a population of 8680 consecutive second-trimester fetuses over 21 months. The fetal bowel was considered hyperechoic if its echogenicity was similar to that of surrounding bone. Follow-up was obtained through medical record review.

RESULTS

Twenty-nine of 50 fetuses (58%) were normal; eight (16%) were aneuploid, including six Down syndrome, one trisomy 13, and one Turner syndrome. All eight fetuses with aneuploidy had sonographic anomalies in addition to the echogenic bowel. Eight of 50 fetuses (16%) were growth-retarded, and five others (10%) had normal karyotypes but are still undelivered. Among the eight growth-retarded fetuses, there were five intrauterine or neonatal deaths, one elective abortion, and two survivors. In addition, the six fetuses with Down syndrome and echogenic bowel represented 12.5% of all second-trimester Down syndrome fetuses karyotyped in our laboratory during the study period. Combining results from the present study (six Down syndrome fetuses) with three studies from the literature (21 additional Down syndrome fetuses), a total of 27 fetuses with echogenic bowel and Down syndrome were identified, 11 (40.7%) of whom had no other sonographic findings. We calculate that if 1,000,000 second-trimester fetuses were scanned, 5105 would have hyperechoic bowel as the only finding, of whom 71 would have Down syndrome and 5034 would not. The risk of Down syndrome in fetuses with isolated hyperechoic bowel is, therefore, 71 in 5105 or 1.4%.

CONCLUSION

The finding of isolated hyperechoic bowel in the second trimester should prompt genetic counseling and consideration of karyotypic analysis.

Prenatal detection of neuroblastoma: a ten-year experience from the Dana-Farber Cancer Institute and Children's Hospital

OBJECTIVES

To assess the relative frequency of, the clinical and pathological correlates in, and the prognosis of the subset of infants with neuroblastoma who were identified initially by prenatal ultrasonography.

DESIGN

Retrospective review of all patients with neuroblastoma evaluated between 1982 and 1992.

SETTING

Large, urban, tertiary care children's hospital in Boston, Massachusetts.

PATIENTS

Eleven infants with neuroblastoma initially detected with prenatal sonograms were identified.

RESULTS

Nine patients had adrenal tumors; two had thoracic paraspinal tumors. Typical diagnostic evidence for neuroblastoma including a palpable abdominal mass and elevations in urinary catecholamines were not commonly seen postnatally. These patients had multiple favorable prognostic indicators including low stage of disease (10/11), favorable biological markers including cellular DNA content (5/5) and N-myc oncogene copy number (5/5), and histopathology suggestive for neuroblastoma in situ (7/11). All patients were treated by surgical resection. One patient exhibited progression of disease postoperatively, but demonstrated a complete clinical response to multiagent chemotherapy. Overall survival in our population was excellent with no deaths seen at a mean follow-up of 37 months (range 3 to 120 months).

CONCLUSIONS

Patients with neuroblastoma identified by prenatal ultrasonography generally, although not exclusively, follow a clinically favorable course in which surgical resection is curative. Chemotherapy is not indicated unless substantial progression of disease occurs.

Human fetal compensatory renal growth

The occurrence of prenatal compensatory renal growth has remained in question, despite the general acceptance of this phenomenon postnatally. We measured by ultrasound imaging the renal length of 22 human fetuses with a solitary kidney or contralateral multicystic dysplastic kidney, and compared it to measurements in 40 normal control fetuses. Renal length was normalized to fetal biparietal diameter. Analysis of covariance showed that the solitary kidneys were significantly larger than normal controls (p < 0.0001), although the rate of growth was not significantly increased above normal. These data document the presence of compensatory renal growth in human fetuses with solitary or functionally solitary kidneys.

Cystic retrocerebellar malformations: unification of the Dandy-Walker complex and the Blake's pouch cyst

Twenty-six cases of developmental retrocerebellar cyst (RCC) formation are studied with respect to determining the usefulness and anatomic relevance of separate terms currently in use, including Dandy-Walker complex, Dandy-Walker malformation, Dandy-Walker variant, mega-cisterna magna (MCM), and Blake's pouch cyst. An anatomic and embryological continuum between Dandy-Walker complex and Blake's pouch cyst is proposed. A method for the useful assessment of RCC is outlined. The patency or closure of the aqueduct is crucial to the evaluation and management of hydrocephalus associated with RCC formation.

Dandy-Walker variant: prenatal sonographic features and clinical outcome

The Dandy-Walker variant is a less severe posterior fossa anomaly than the classic Dandy-Walker malformation. In 17 consecutive fetuses, the Dandy-Walker variant was diagnosed at sonography, and associated defects, karyotypic anomalies, and outcomes were evaluated. Four of the 17 fetuses (24%) had mild ventriculomegaly. Eight of the 17 (47%) had concurrent non-central nervous system (CNS) anomalies. Five fetuses (29%) had an abnormal karyotype (two with trisomy 18, one each with trisomy 13, 21, and 11q+) and associated sonographic anomalies. Six of the 17 fetuses (35%) died in utero or during the neonatal period, two are severely handicapped, and the other nine are developing normally at ages 4 months to 4 years. Six of the nine normally developing infants (53%) lacked non-CNS sonographic findings. Because the prognosis is uncertain for an infant born with the prenatal diagnosis of Dandy-Walker variant, prenatal recognition of the anomaly allows for the option of fetal karyotyping and for arrangement for postnatal follow-up.

Isolated choroid plexus cysts in the second-trimester fetus: is amniocentesis really indicated?

Choroid plexus (CP) cysts have been associated with trisomy 18, although most fetuses with CP cysts are normal. Since many fetuses with trisomy 18 have other sonographic abnormalities, the necessity of obtaining a karyotype for all fetuses with isolated CP cysts remains controversial. The authors prospectively studied 234 second-trimester fetuses with sonographically discovered CP cysts. Two hundred twenty of them had no other sonographic findings. None of these 220 normal fetuses had evidence of aneuploidy at amniocentesis or an anomaly at birth. Fourteen fetuses had major anomalies detected in utero: 11 had trisomy 18, one had triploidy, and two had normal karyotypes but were structurally abnormal. While size and bilaterality of the CP cysts were not helpful in predicting aneuploidy, the meticulous anatomic survey of fetuses with CP cysts allowed successful identification of all aneuploid fetuses. These data show that the yield of abnormal karyotypes in fetuses with isolated CP cysts is low and may not justify the risk of amniocentesis.

Prenatal diagnosis of the megacystis-megaureter association

A total of 11 male neonates with hydronephrosis and a large bladder in utero had the megacystis-megaureter association. Prenatal ultrasound findings included bilateral hydroureteronephrosis; a large, smooth, thin-walled bladder, and normal volume of amniotic fluid. Postnatal studies demonstrated grades 4 to 5 bilateral reflux, a large bladder without obstruction and in 2 infants nonfunction of a kidney or renal moiety. Of 7 infants initially managed nonoperatively 5 have undergone surgery due to persistent reflux or breakthrough urinary infections. The prenatal diagnosis of the megacystis-megaureter association can be suspected with reasonable accuracy. Prompt postnatal continuous antibiotic prophylaxis and uroradiological confirmation allow for nonemergency management of this condition with excellent results.

The natural history of oligohydramnios/polyhydramnios sequence in monochorionic diamniotic twins

Twelve patients with monochorionic diamniotic twin pregnancies complicated by oligohydramnios/polyhydramnios sequence were evaluated to determine the natural history of this syndrome. Nine patients elected to continue their pregnancies and three underwent elective termination. Six of the nine continuing pregnancies delivered viable fetuses. Four of the nine continuing pregnancies had evidence of a 'stuck' twin at less than 20 weeks' gestation, and only one yielded live newborns (25%). Three patients diagnosed with a mild case of oligohydramnios/polyhydramnios sequence underwent worsening of the syndrome with a 'stuck' twin seen only after 26 weeks: all neonates survived. Five pregnancies initially diagnosed as having a 'stuck' twin showed improvement in amniotic fluid volume, with one actually reversing, so that the previously 'stuck' twin developed polyhydramnios and the co-twin became 'stuck'. In summary, among the nine non-aborted pregnancies managed conservatively, 12 of 18 fetuses (67%) survived. When the diagnosis of 'stuck' twin was made at <or= 20 weeks, only two of eight (25%) lived. These observations suggest that the oligohydramnios/polyhydramnios sequence is a dynamic process with wide and often unpredictable fluctuations in amniotic fluid volume.

Late onset severe oligohydramnios associated with genitourinary abnormalities

We evaluated the diagnosis, gestational age at presentation, timing and mode of delivery, and ultimate outcome in those fetuses with third trimester onset of severe oligohydramnios who also had urinary tract abnormalities. A total of 8 fetuses with obstructive uropathy or cystic renal disease was seen during a 2-year period with the onset of severe oligohydramnios noted between 27 and 33 weeks. Immediate and late postnatal pulmonary function was excellent in 5 of the 8 subjects. Three neonates had respiratory distress but only 1 died at birth. Ultimate renal function varied in the 7 survivors. Those with supravesical obstructive uropathy achieved a normal serum creatinine, while the neonates with renal cystic disease and infravesical obstruction did not.

Prevalence of cystic fibrosis in fetuses with dilated bowel

The authors reviewed the ultrasonographic images and medical records of 15 consecutive fetuses with dilated loops of bowel distal to the duodenum and determined the prevalence of cystic fibrosis among them. The criteria for dilated bowel loops included both subjective criteria and luminal measurements. Five of the fetuses (33%) had cystic fibrosis. Eleven had bowel obstruction at birth, and four of those 11 (36%) also had cystic fibrosis. One of the four fetuses without bowel obstruction at birth had cystic fibrosis. There were no differences in sonographic findings between fetuses with and without cystic fibrosis, except that one third-trimester fetus with cystic fibrosis had echogenic small bowel with shadowing. All of the fetuses with dilated bowel loops persisting at birth required surgery. Further studies are indicated to determine the exact risk of cystic fibrosis in this population.

Fetal echocardiography: accuracy and limitations in a population at high and low risk for heart defects

OBJECTIVE

Our objective was to assess the accuracy of prenatal echocardiography in detecting congenital heart defects in patients at high and low risk for structural cardiac anomalies.

STUDY DESIGN

Sixty-nine consecutive fetuses with congenital heart defects who had had prenatal ultrasonography at greater than or equal to 18 weeks' gestation were evaluated to determine the accuracy of prenatal ultrasonography in identifying structural cardiac defects. Thirty-nine patients were at high risk and 30 patients were at low risk for cardiac anomalies. All fetuses were scanned with standard four-chamber and outflow tract views. Data concerning extracardiac anomalies and karyotypic abnormalities were tabulated. The accuracy of the four-chamber view alone in identifying congenital heart defects was evaluated.

RESULTS

Fifty-seven of 69 fetuses (83%) were prenatally identified ultrasonographically as having a heart defect. There was no difference in the sensitivity of detecting cardiac anomalies between high-risk and low-risk groups. When the four-chamber view was used, only 63% of fetuses were recognized as having an abnormal heart. Extracardiac anomalies were noted in 36% and karyotypic abnormalities in 17% of patients.

CONCLUSION

The four-chamber and outflow tract views done routinely in an ultrasonography laboratory seeing a mixed population of patients was successful in detecting 83% of fetuses with structural cardiac malformations. Because 43% of the fetuses with heart defects were referred for low-risk indications, systematic ultrasonographic examination of the fetal heart should not be reserved only for those at high risk.

Fetal meconium peritonitis without sequelae

Meconium peritonitis is a chemical peritonitis usually resulting from antenatal bowel rupture. Prenatal ultrasound findings include ascites, intraabdominal masses, bowel dilatation and the development of intraabdominal calcifications [1-5]. The most common bowel disorders which lead to meconium peritonitis in utero are those resulting in bowel obstruction and perforation, such as small bowel atresias, volvulus and meconium ileus [1-5]. Meconium ileus is associated with cystic fibrosis in most cases, although extraluminal abdominal calcifications are usually scarce in cases of cystic fibrosis [1, 6]. Postnatal outcome for infants with meconium peritonitis depends on the etiology for bowel rupture and underlying disease.

Increased renal parenchymal echogenicity in the fetus: importance and clinical outcome

Pre- and postnatal ultrasound (US) findings and clinical course in 19 fetuses (16-40 menstrual weeks) with hyperechoic kidneys (renal echogenicity greater than that of liver) and no other abnormalities detected with US were evaluated to determine whether increased renal parenchymal echogenicity in the fetus indicates renal disease. Four infants (21%) were healthy at birth and had normal postnatal sonograms. Another 10 infants (53%) survived, but abnormalities were found at neonatal US. Postnatal diagnoses in these 10 neonates included unilateral renal dysplasia (n = 3), unilateral multicystic dysplastic kidney and a contralateral hyperechoic kidney (n = 2), hydronephrosis (n = 2), and renal abnormalities of unknown type (n = 3). Five fetuses with either infantile polycystic kidney disease (n = 4) or bilateral multicystic dysplasia (n = 1) did not survive. Oligohydramnios was predictive of a poor prognosis. Hyperechoic renal parenchyma in the fetus was associated with sonographic or functional abnormalities in 15 of 19 cases (79%) and a 74% survival rate.

Structural genitourinary defects detected in utero

Fetal genitourinary anomalies are detected with increasing frequency due to the large numbers of fetuses that undergo screening ultrasonography (US) for nonspecific indications. One hundred seventy-seven patients were evaluated for fetal urinary abnormalities over a 2-year period. Fetal hydronephrosis accounted for 154 (87%) of the cases, with the remaining diagnoses including multicystic dysplastic kidney, autosomal recessive polycystic kidney disease, and renal agenesis or hypodysplasia. Ureteropelvic junction obstruction was the most common postnatal anatomic abnormality (29%), with a large number of cases of prenatally diagnosed hydronephrosis resolving either prenatally (33%) or postnatally (24%). Prenatal US findings were retrospectively analyzed with regard to the degree of hydronephrosis at different stages of gestation. Data showed that there is a gradual rise in anteroposterior renal pelvic diameter during gestation and that there is a correlation between this diameter and the ultimate renal outcome in regard to surgical repair. This information can provide guidance in making recommendations to parents and physicians.

Fetal pyelectasis: a possible association with Down syndrome

Two hundred ten consecutive fetuses were identified as having renal pyelectasis among 7400 patients scanned during 1 year. Seven of these 210 fetuses had Down syndrome. We reviewed images of the kidneys of 44 fetuses with Down syndrome collected over 5 years and found that 25% of these affected fetuses had pyelectasis. The incidence of Down syndrome was 3.3% when fetal pyelectasis was present.

Abnormal karyotype of fetuses with omphalocele: prediction based on omphalocele contents

The majority of fetuses with omphalocele have other congenital abnormalities and, in many cases, an abnormal karyotype. We retrospectively studied 22 consecutive fetuses with sonographically diagnosed omphalocele and available karyotype to determine whether the contents of the omphalocele could predict the karyotype. Of these 22 fetuses, 18 had normal and four had abnormal karyotypes. Sixteen of the karyotypically normal fetuses had liver herniated into the omphalocele and two had only bowel present in the defect. All four of the fetuses with abnormal chromosomes had only bowel in the defect.

Neurological complications of hemolytic-uremic syndrome

Of 78 children identified with hemolytic-uremic syndrome at the Children's Hospital, Boston, from 1976 to 1986, 16 patients (20.5%) had neurological manifestations during their hospitalization. The most common manifestations were significant alterations in consciousness (coma, stupor) in 12 patients, and either generalized or partial seizures in ten patients. Others included hemiplegia (4 patients), decerebrate posturing (3), cortical blindness (2), hallucinations (1), and dystonic posturing (1). Cranial computed tomographic scans were abnormal in eight of 11 patients scanned. The abnormalities included diffuse cerebral edema (4 patients), large vessel infarctions (3), diffuse multiple small infarcts (4), and multiple hemorrhages (1). Five patients died as a result of their central nervous system complications, and six had neurological sequelae at discharge. Five patients recovered and at discharge had no evidence of neurological dysfunction.