Isolated ventricular septal defects in the era of advanced fetal echocardiography: risk of chromosomal anomalies and spontaneous closure rate from diagnosis to age of 1 year.

OBJECTIVES: To evaluate, in a cohort of 248 fetuses seen at a tertiary referral center, the frequency of isolated ventricular septal defects (VSD) among all congenital heart defects (CHD), the association with chromosomal and postnatal anomalies and the rate of spontaneous closure. METHODS: This was a 6-year study on 10,800 women referred for fetal echocardiography, with 995 confirmed cases of CHD. The prevalence and characteristics of VSDs were analyzed, including follow-up until 1 year of age. Multivariate binary logistic regression analysis was performed to test the independent contribution of the ratio of the diameter of the VSD to that of the aorta (VSD/aorta ratio) (< 0.5 or ≥ 0.5) and location of VSD (perimembranous or muscular) in the prediction of spontaneous closure before the age of 1 year. RESULTS: Two hundred and forty-eight VSDs (24.9% of all CHDs) were diagnosed, of which 216 (87.1%) were muscular and 32 (12.9%) perimembranous. Median gestational age at diagnosis was 30.4 (range, 17-41) weeks and mean size 2.6 ± 0.77 mm. Clinically relevant chromosomal anomalies were found in one (3.1%) perimembranous VSD compared with none in 216 muscular defects (P = 0.12). Postnatal malformations were diagnosed in eight of the 211 cases (3.8%) evaluated at 12 months postpartum. Spontaneous closure occurred prenatally in 13 fetuses (5.2%) and postnatally in 151 of the 198 infants (76.3%) who had an open VSD at birth. Closure was predicted by the VSD/aorta ratio (odds ratio (OR) 0.445 (95% CI, 0.216-0.914); P < 0.03) and location (OR 0.385 (95% CI, 0.160-0.926); P < 0.03). CONCLUSIONS: In our fetal cardiology unit, isolated muscular VSD is today the most prevalent CHD. In contrast to the findings of postnatal studies, muscular VSDs were more common than perimembranous VSDs. Perimembranous VSDs were associated with a higher risk of chromosomal anomalies than were muscular VSDs, which had a similar risk to those of normal pregnancies. Spontaneous closure of the VSD was frequent and occurred in most cases postnatally.

Accuracy of four-dimensional spatiotemporal image correlation echocardiography in the prenatal diagnosis of congenital heart defects.

OBJECTIVE: To evaluate the accuracy of four-dimensional (4D) spatiotemporal image correlation (STIC) echocardiography for the diagnosis of fetal congenital heart disease (CHD) in a selected high-risk population. METHODS: Three hundred and sixty-three pregnant women referred for suspected CHD on screening ultrasound were evaluated by means of conventional echocardiography between 14 and 41 weeks' gestation and 4D-STIC volumes were obtained (including gray-scale and color Doppler information). Stored volumes were analyzed, at least 1 year after they had been acquired, by examiners blinded to the patients' identities and outcomes. The STIC diagnoses were compared to those made on conventional two-dimensional echocardiography and the accuracy of diagnosis was assessed with respect to postnatal examination, or autopsy in cases of termination of pregnancy or perinatal death. RESULTS: The mean gestational age at volume acquisition was 24 + 5 weeks. STIC evaluation was possible in 98% of cases. Twenty-one cases were lost to follow-up, with a total of 167 normal hearts and 175 cases of CHD diagnosed at postnatal evaluation. The overall accuracy, sensitivity, specificity and positive and negative predictive values of STIC in determining the presence or absence of CHD were 91.6, 94.9, 88.1, 89.7 and 94.0%, respectively. Absolute concordance with the final specific diagnosis among cases with confirmed CHD was 74.3% for STIC echocardiography, compared with 81.7% for real-time evaluation. CONCLUSION: 4D-STIC echocardiography performed by experienced operators can be used in fetuses at risk for cardiac anomalies in order to reliably provide reassurance of normality or to accurately diagnose major structural heart defects.

The 'question mark' sign as a new ultrasound marker of tetralogy of Fallot in the fetus.

OBJECTIVE: To describe a new ultrasonographic marker, the 'question-mark' sign, to assist in the diagnosis of tetralogy of Fallot (TOF) in the fetus, and to evaluate its prevalence in TOF as compared with other cardiac defects. METHODS: A prospective evaluation over a 5-year period of a consecutive series of 3998 pregnant women undergoing fetal echocardiography from 12 to 40 weeks' gestation due to high risk for congenital heart disease (CHD). Standard echocardiographic planes with color Doppler assessment and evaluation of the whole aortic arch, from the left ventricular outflow tract to the descending aorta in the axial upper mediastinum views, were performed. The question-mark sign corresponded with an enlarged and dilated ascending aorta and aortic arch in the three-vessel view of the upper fetal mediastinum. The frequency of this sign was evaluated in cases with TOF and in other cases of cardiac defects, as well as in fetuses with normal cardiac scans in this series. RESULTS: CHD was diagnosed in a total of 447 (11.2%) fetuses at a median gestational age of 24 (range, 12-40) weeks. Forty-two of the 447 (9.4%) had TOF, of which 29 cases (69.0%) had classical TOF (pulmonary stenosis), nine (21.4%) pulmonary atresia and four (9.5%) absent pulmonary valve syndrome. A question-mark sign was observed in 16/29 (55.2%) cases of classical TOF and in 8/9 (88.9%) cases of TOF with pulmonary atresia. The sign was never observed in any of the cases of TOF with a right-sided aortic arch. Likewise, the sign was observed in 1/405 (0.2%) cases with other cardiac anomalies (a fetus with a complex cardiac defect) and in none of the fetuses with normal hearts. CONCLUSIONS: The finding of an enlarged aorta with a question-mark shape should raise a strong suspicion of tetralogy of Fallot, in particular the variant with pulmonary atresia. This sign may be useful in screening considering that prenatal diagnosis of TOF by routine ultrasonography remains a challenge.

Intra- and interobserver repeatability of fetal cardiac examination using four-dimensional spatiotemporal image correlation in each trimester of pregnancy.

OBJECTIVE: To assess the intra- and interobserver repeatability of the evaluation of fetal cardiac structures and measurements using spatiotemporal image correlation (STIC) technology in each trimester of pregnancy. METHODS: Four-dimensional (4D)-STIC volumes from 150 low-risk pregnancies were acquired at first-, second- or third-trimester scan for later analysis by two different reviewers. A total of 19 items, including the evaluation of 14 structures as well as five measurements of the fetal heart, were evaluated. The reliability of qualitative variables was evaluated using Cohen's kappa and absolute agreement analysis while that of quantitative parameters was assessed using the intraclass correlation coefficient (ICC). RESULTS: Forty-five, 47 and 47 STIC volumes were included in the final analysis from the first, second and third trimesters, respectively. For the evaluation of cardiac structures, good or excellent intra- and interobserver agreement (kappa > 0.6) was obtained in 12/14 and 9/14, respectively, while absolute agreement was > 90% for most structures evaluated. Regarding the quantitative cardiac measurements, ICC values were above 0.90 for all but cardiac axis (intraobserver ICC, 0.81 and interobserver ICC, 0.61). There were no significant differences in the repeatability values observed for qualitative or quantitative parameters among the trimesters of pregnancy. CONCLUSION: Cardiac examination from 4D-STIC volumes showed a high repeatability between and within observers in each trimester of pregnancy.

Feasibility and accuracy of fetal echocardiography using four-dimensional spatiotemporal image correlation technology before 16 weeks' gestation.

OBJECTIVES: To evaluate the potential value of early fetal echocardiography (EFE) by means of four-dimensional (4D) spatiotemporal image correlation (STIC) technology for either reassurance of normality or prenatal diagnosis of major congenital heart defects (CHDs). METHODS: Sixty-nine pregnant women from 11 to 15 weeks' gestation underwent EFE. 4D-STIC volumes were acquired by the transvaginal approach for later review by two different examiners. STIC evaluation was considered complete when the four-chamber view, and the origin and double-crossing of the great arteries were identified correctly. Color Doppler imaging was used to detect either septal shunts or transvalvular regurgitation/aliasing suggesting abnormalities. STIC diagnoses were compared with those of conventional EFE. Reliability was assessed by postnatal examination, or autopsy in cases of termination of pregnancy or perinatal death. RESULTS: The median gestational age at volume acquisition was 13 + 3 weeks. Eleven (15.9%) cases of CHD were diagnosed. A complete EFE was possible in 64 cases. We were able to provide reassurance of normality in 51 of the 53 confirmed normal hearts, with no false-positive results for major defects, although two minor defects (one ventricular septal defect (VSD) and one persistent left superior vena cava) were falsely suspected. The only false negative was a significant VSD at birth overlooked by both observers. Therefore, the total accuracy of STIC-EFE was 95.3% (61/64), with sensitivity, specificity, and positive and negative predictive values of 90.9%, 96.2%, 83.3% and 98.1%. The accuracy of conventional EFE (98.4%, 63/64) was slightly better than that of STIC, with no false-positive results recorded. CONCLUSIONS: Offline evaluation of 4D-STIC acquired volumes of the fetal heart in the first and early second trimester of pregnancy is reliable not only for early reassurance of normal cardiac anatomy but also to diagnose most major structural heart defects.

Doppler assessment of the aortic isthmus and perinatal outcome in preterm fetuses with severe intrauterine growth restriction.

OBJECTIVES: To evaluate the characteristics and association with perinatal outcome of the aortic isthmus (AoI) circulation as assessed by Doppler imaging in preterm growth-restricted fetuses with placental insufficiency. METHODS: This was a prospective cross-sectional study. Fifty-one fetuses with intrauterine growth restriction (IUGR) and either an umbilical artery (UA) pulsatility index (PI) > 95(th) centile or a cerebroplacental ratio < 5(th) centile were examined at 24-36 weeks' gestation. AoI impedance indices (PI and resistance index) and absolute velocities (peak systolic (PSV), end-diastolic and time-averaged maximum (TAMXV) velocities), were measured in all cases and compared with reference ranges by gestational age. Furthermore, fetuses were stratified into two groups according to the direction of the diastolic blood flow in the AoI: those with antegrade flow (n = 41) and those with retrograde flow (n = 10). Clinical surveillance was based on gestational age and Doppler assessment of the UA, middle cerebral artery and ductus venosus (DV). Adverse perinatal outcome was defined as stillbirth, neonatal death and severe morbidity (respiratory distress syndrome, bronchopulmonary dysplasia, Grade III/IV intraventricular hemorrhage, necrotizing enterocolitis and a neonatal intensive care unit stay > 14 days). RESULTS: Adverse perinatal outcome was significantly associated with an increased AoI-PI (area under the curve 0.77; 95% CI, 0.63-0.92; P < 0.005). A significant correlation (P < 0.001) was found between retrograde blood flow in the AoI and adverse perinatal outcome, the overall perinatal mortality being higher in the retrograde group (70% vs. 4.8%, P < 0.001). In 4/5 (80%) fetuses the reversal of flow in the AoI preceded that in the DV by 24-48 h. AoI-PSV and AoI-TAMXV were < 5(th) centile in 40/51 (78%) and 48/51 (94%) cases, respectively, whereas AoI-PI was > 95(th) centile in 21/51 (41%) cases. CONCLUSIONS: Retrograde flow in the AoI in growth-restricted fetuses correlates strongly with adverse perinatal outcome. Absolute velocities in the AoI are decreased in growth-restricted fetuses. The data suggest a potential role for Doppler imaging of the AoI in the clinical surveillance of fetuses with severe IUGR, which should be confirmed in larger prospective studies.