Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects.

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects.

Prenatal Congenital Heart Disease and Placental Phenotypes: Preserved Neonatal Weight Despite Small Placentas.

Background: Congenital heart disease (CHD) affects 8 in 1,000 live births with significant postnatal implications including growth failure, neurodevelopmental delay, and mortality. The placenta develops concomitantly with the fetal heart. High rates of placental pathology and discordant growth in pregnancies affected by CHD highlight the significance of the fetal-placental-cardiac axis. Objectives: This study aimed to characterize the relationship between neonatal birthweight (BW), head circumference, placental weight (PW), and placental pathology in pregnancies affected by CHD. PW:BW provides a surrogate to assess placental efficiency, or nutrient exchange and delivery by the placenta, across CHD phenotypes. Methods: Retrospective cohort of 139 live-born singletons with postnatally confirmed CHD with placental pathology. Placental examination, infant BW, head circumference, and CHD categories (septal defects, right-sided defects, left-sided defects, conotruncal anomalies, and others) were included. Chi-square, Fisher's exact, or Kruskall-Wallis tests and multinomial logistic regressions, as appropriate. Results: Median birthweight and head circumference percentile was 33 and 35, respectively. Placental pathology was documented in 37% of cases. PW to BW ratios were <10th percentile for 78% and <3rd percentile for 54% of the cohort, with no difference between CHD categories (P = 0.39 and P = 0.56, respectively). Conclusions: Infants with CHD have preserved BW and head circumferences in the setting of small placentas and increased prevalence of placental pathology, suggesting placental efficiency. Detection of abnormal placental growth could add prenatal diagnostic value. Placental and neonatal discordant growth may allude to a vascular anomaly predisposing fetuses to developing CHD. Further studies are needed to explore fetal nutrient delivery and utilization efficiency.