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.     

Genetic diagnoses and associated anomalies in fetuses prenatally diagnosed with esophageal atresia

Esophageal atresia (EA) is a congenital anomaly occurring in 2.3 per 10,000 live births. Due to advances in prenatal imaging, EA is more readily diagnosed, but data on the associated genetic diagnoses, other anomalies, and postnatal outcome for fetuses diagnosed prenatally with EA are scarce. We collected data from two academic medical centers (n = 61). Our data included fetuses with suspected EA on prenatal imaging that was confirmed postnatally and had at least one genetic test. In our cohort of 61 cases, 29 (49%) were born prematurely and 19% of those born alive died in the first 9 years of life. The most commonly associated birth defects were cardiac anomalies (67%) and spine anomalies (50%). A diagnosis was made in 61% of the cases; the most common diagnoses were vertebral defects, anal atresia, cardiac anomalies, tracheoesophageal fistula with esophageal atresia, radial or renal dysplasia, and limb anomalies association (43%, although 12% met only 2 of the criteria), trisomy 21 (5%), and CHARGE syndrome (5%). Our findings suggest that most fetuses with prenatally diagnosed EA have one or more additional major anomaly that warrants a more comprehensive clinical genetics evaluation. Fetuses diagnosed prenatally appear to represent a cohort with a worse outcome.     

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 thoracic abnormalities: MR imaging

PURPOSE: To elucidate the appearance of fetal thoracic abnormalities at prenatal magnetic resonance (MR) imaging and determine whether MR imaging yields information additional to that obtained with ultrasonography (US). MATERIALS AND METHODS: US and MR imaging data from 83 MR examinations of 74 fetuses with thoracic abnormalities and confirmatory US performed within 1 week before MR imaging were compared with respect to resulting changes in patient counseling and/or care. Lung parenchyma and lesion signal intensities and vascularity, airway, esophagus, and diaphragm appearances were reviewed retrospectively on MR images. Student t tests and analyses of variance were performed. RESULTS: MR imaging yielded information additional to that acquired with US in 28 (38%) of 74 fetuses. The additional findings were confirmed in 19 of the 28 fetuses at postnatal follow-up; no follow-up data were available for the other nine fetuses. Thoracic MR information affected care with regard to six (8%) of 74 fetuses. Mean gestational age of 15 fetuses with lung signal intensity (SI) slightly lower than that of amniotic fluid (28.4 weeks +/- 6.8 [SD]) at T2-weighted MR imaging was significantly older than that of 18 fetuses with intermediate SI (21.3 weeks +/- 4.3) (P <.05). Mean SI of 13 congenital cystic adenomatoid malformations (CCAMs) and/or sequestrations (1.74 +/- 1.05) at T2-weighted MR imaging was significantly higher than that of the normal lungs of 33 fetuses (2.63 +/-.63) (P <.001). Among nine studies in which vessels were visualized in CCAMs and/or sequestrations, six involved a normal vascular branching pattern. Portions of the esophagus were seen in 31 (36%) of 85 fetuses. Nonvisualization of a major airway was not sufficient for diagnosis of pulmonary atresia. Visualization of a portion of the esophagus did not correlate with esophageal atresia. In all except one fetus, who had anhydramnios and pulmonary hypoplasia, and the fetuses with congenital diaphragmatic hernia, at least a portion of the diaphragm was visualized at MR imaging. CONCLUSION: MR imaging yields information additional to that yielded with US in fetuses with thoracic abnormalities.     

The Distended Fetal Hypopharynx: A Sensitive and Novel Sign for the Prenatal Diagnosis of Esophageal Atresia

Background/Purpose

Although advances have been made in the prenatal diagnosis of esophageal atresia (EA), most neonates are not identified until after birth. The distended hypopharynx (DHP) has been suggested as a novel prenatal sign for EA. We assess its diagnostic accuracy and predictive value on ultrasound (US) and magnetic resonance imaging (MRI), both alone and in combination with the esophageal pouch (EP) and secondary signs of EA (polyhydramnios and a small or absent fetal stomach).