Ductus Venosus S‐Wave/Isovolumetric A‐Wave (SIA) Index and A‐Wave Reversed Flow in Severely Premature Growth‐Restricted Fetuses

Objective. Ductus venosus (DV) Doppler waveforms show 2 periods of decreased velocity during iso‐volumetric relaxation (isovolumetric relaxation velocity [IRV]) and atrial contraction (A wave or end‐diastolic velocity [EDV]). In intrauterine growth‐restricted (IUGR) fetuses, both may become abnormal. The hypothesis for this study was that in severely premature IUGR fetuses, Doppler assessment of both the IRV and EDV allows a more accurate prediction of fetal outcome than absent/reversed end‐diastolic flow (A/REDF) alone. Methods. Ductus venosus Doppler waveforms were serially studied in 49 severely premature IUGR fetuses from diagnosis until death or delivery. The DV waveforms were assessed for peak systolic velocity (PSV), IRV, and EDV and qualitatively for forward end‐diastolic flow or A/REDF. The S‐wave/isovolumetric A‐wave (SIA) index [PSV/(IRV + EDV)] for each fetus was compared to fetal/neonatal outcomes. Results. There were 8 cases of fetal death (FD), 9 cases of neonatal death (ND), and 32 cases of neonatal survival (NS). A receiver operating characteristic (ROC) curve for the SIA index in all cases showed that values less than ?1.25 correlated with FD and those greater than ?1.25 correlated with live birth, with 100% sensitivity and 100% specificity. A second ROC curve of live births showed that values less than 2.07 correlated with NS and those greater than 2.07 correlated with ND with 67% sensitivity and 94% specificity. Ductus venosus A/REDF correlated with FD, ND, and NS with sensitivity values of 88%, 78%, and 32%, respectively. Of the 32 NSs, 11 (34%) had A/REDF with a median of 11 days before delivery. Conclusions. The SIA index is a novel Doppler parameter for assessment of severely premature IUGR fetuses that allows a much more accurate prediction of fetal outcome compared to A/REDF alone.     

Application of the 3‐Vessel View in Routine Prenatal Sonographic Screening for Congenital Heart Disease

Objectives. The purpose of this study was to evaluate the diagnostic accuracy of prenatal screening for congenital heart disease (CHD) based on a combination of the 4‐chamber view and 3‐vessel view in an unselected population. Methods. A prospective study on 8025 scanned fetuses was performed. All singleton pregnancies scheduled for routine prenatal sonographic screening at 20 to 24 weeks' gestation and subsequently delivered in our unit were included. Data were recorded regarding visualization of the 4‐chamber view, outflow tracts, and 3‐vessel view. Suspected CHD was confirmed by postmortem or postnatal echocardiography. We obtained follow‐up data for the neonates and calculated the diagnostic accuracy of the examinations. Results. Major CHD was identified in 32 cases (4.0%), of which 26 (81.3%) were diagnosed antenatally and 6 (18.7%) postnatally. Four cases (0.5%) had false‐positive findings. Twenty‐one cases were identified by the 4‐chamber view and 5 by an abnormal 3‐vessel view. The sensitivity of the 4‐chamber view alone was 65.6%, and the specificity was 99.9%. The sensitivity of the combination of the 4‐chamber view and 3‐vessel view was 81.3%, and the specificity was 99.9%. Conclusions. The 3‐vessel view is a reliable and easy method to be used in a routine antenatal clinic along with the 4‐chamber view.     

Role of the 3‐Vessel and Trachea View in Antenatal Detection of Tetralogy of Fallot

Prenatal diagnosis of tetralogy of Fallot remains less frequent compared to other major congenital heart defects. In this study, we examined how often the 3‐vessel and trachea view was abnormal in a large series of prenatally diagnosed cases of tetralogy of Fallot. In addition, we compared its sensitivity to that of the traditional outflow tract views for detection of tetralogy of Fallot. We found that both views were abnormal in all fetuses with tetralogy of Fallot, showing reversed aortic‐to‐pulmonary valve and aortic arch isthmus‐to‐ductus arteriosus ratios in the outflow tract and 3‐vessel and trachea views, respectively. However, as a single measured marker, the enlarged aortic arch isthmus on the 3‐vessel and trachea view appears to be the most sensitive for tetralogy of Fallot.     

Use of 3‐Dimensional Sonography for Prenatal Evaluation and Follow‐up of Fetal Goitrous Hypothyroidism

Objective. Fetal goitrous hypothyroidism is a rare and potentially lethal condition. Consequently, its early diagnosis and treatment improve prognosis. Thyroid hormone measurement in either fetal serum or amniotic fluid implies important risks. Here we present a fetal goiter and the follow‐up procedure, both done by the traditional method and by using 3‐dimensional power Doppler (3DPD) imaging and virtual organ computer‐aided analysis (VOCAL). Methods. A single well‐documented case of fetal goiter was followed weekly from 22 weeks until delivery. Amniocentesis for thyrotropin (TSH) and free thyroxine (T₄) measurement as well as levothyroxine injections were performed at every control. In addition to amniocentesis, every control involved a sonographic evaluation, which included standard measurements of the gland and the capture of volume image sets in gray scale and 3DPD. Volume calculation of the gland was done using VOCAL software. Vascularization of the gland was evaluated by the vascularization index (VI) included in the software. Results. With treatment, TSH levels decreased progressively until normalization. Free T₄ levels increased toward the end of gestation. Sonographic measurements of the gland volume to estimated fetal weight ratio decreased across treatment as levels of TSH did. The VI clearly depicted the vascular regression of the goiter, decreasing throughout treatment in a consistent way until 24 hours before delivery. Conclusions. Gray scale and 3DPD evaluations of the thyroid gland have been validated under similar circumstances and might be reliable complements to the invasive methods used in the management of this fetal condition.     

Cerebroplacental Doppler ratio and adverse perinatal outcomes in intrauterine growth restriction: evaluating the impact of using gestational age-specific reference values.

OBJECTIVE: The purpose of this study was to compare the impact of using gestational age-specific reference levels of the cerebroplacental Doppler ratio (CPR) with categorical threshold in the prediction of adverse perinatal outcomes in growth-restricted pregnancies. METHODS: A retrospective cohort study of cases of intrauterine growth restriction over a 3-year period was conducted. The umbilical artery and middle cerebral artery pulsatility indices were converted to CPRs. The efficacy of using gestational age-specific reference levels of CPRs in predicting adverse outcomes was compared with the use of a CPR of less than 1.08. Adverse perinatal outcomes evaluated included cesarean delivery for nonreassuring fetal heart tones, umbilical artery pH less than 7.0, 5-minute Apgar scores less than 7.0, intraventricular hemorrhage greater than grade 2, periventricular leukomalacia, respiratory distress syndrome, and perinatal death. RESULTS: Of 183 pregnancies meeting our inclusion criteria, there were 70 with at least 1 adverse outcome. With the use of a CPR ratio below the 5th percentile for gestational age, the sensitivity, specificity, and positive and negative predictive values for predicting an adverse outcome were 65%, 73%, 73%, and 65%, respectively, with an odds ratio (95% confidence interval) of 5.2 (1.4-19.4; area under the receiver operating characteristic curve, 0.69). With a CPR threshold of less than 1.08, the sensitivity, specificity, and positive and negative predictive values were 72%, 62%, 68%, and 67%, with an odds ratio (95% confidence interval) of 4.2 (1.2-15.3; area under the receiver operating characteristic curve, 0.67). CONCLUSIONS: An abnormal CPR is associated with adverse perinatal outcomes in growth-restricted fetuses. The accuracy of using gestational age-specific reference levels was similar to that of using a categorical threshold.     

Aorta Larger Than Pulmonary Artery in the Fetal 3‐Vessel View

Objective. Fetal great artery asymmetry may accompany congenital heart disease. The fetal echocardiographic 3‐vessel view (3VV) allows assessment of the superior vena cava, ascending aorta (AA), and main pulmonary artery (MPA). Our aim was to determine the association of congenital heart disease in fetuses with an AA/MPA ratio of greater than 1. Methods. We electronically searched our fetal echocardiographic database for studies performed between March 2002 and January 2008 that showed 3VVs with AA/MPA ratios of greater than 1 and correlated the findings with the presence of congenital heart disease. Results. In 2797 fetal echocardiograms, we identified 31 fetuses with normal 4‐chamber views showing AA/MPA ratios of greater than 1 in the 3VV. Of 31 fetuses, 25 (81%) had tetralogy of Fallot (ToF) or a ToF variant, and 6 (19%) had an aortic valve abnormality or isolated dilatation of the AA. Conclusions. Screening obstetric fetal sonography showing a 3VV AA/MPA ratio of greater than 1 suggests congenital heart disease and indicates the need for comprehensive fetal echocardiography.     

Utility of the 3‐Vessel and 3‐Vessel and Trachea Views in Prenatal Diagnosis of a Pulmonary Artery Sling

A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling.