Pulmonary hypoplasia in fetuses with congenital conotruncal defects

Patterns of Aortic Dilation in Tetralogy of Fallot: An Analysis of 100 Fetal Echocardiograms Compared With Matched Controls

Background Although aortic dilation is common in tetralogy of Fallot (TOF), its progression and risk of dissection are not well understood. The mechanism of dilation is primarily attributed to increased flow in utero; an alternative is unequal septation of the truncus arteriosus resulting in a larger aorta and inherently hypoplastic pulmonary artery (PA). If the latter is true, we hypothesize the aorta to PA ratio in TOF is stable throughout gestation, and sums of great artery dimensions are similar to controls. Methods and Results We performed a single-center retrospective study of fetuses with TOF (2014-2020) and matched controls. We compared sums of diameters, circumferences, and cross-sectional areas of the aorta and PA and evaluated the aorta to PA ratio across gestation in 2 TOF subtypes: pulmonary stenosis and atresia (TOF-PA). There were 100 echocardiograms with TOF (36% TOF-PA) with median gestational age of 31 weeks (interquartile range 26.5-34.4) and median maternal age of 34 years (interquartile range 30-37). There were no differences in sums of great artery dimensions between TOF-pulmonary stenosis and controls. In TOF-PA, sums were significantly lower than controls (P values <0.01). The aorta to PA ratio was stable throughout gestation (Pearson's r=0.08 [95% CI, -0.12 to 0.27], -0.06 [95% CI, -0.25 to 0.14]). Conclusions The aorta in fetal TOF is large but grows proportionally throughout gestation, with sums of great artery dimensions similar to controls. TOF-PA appears distinct from TOF-pulmonary stenosis (with smaller sums), warranting further investigation. In conclusion, our findings suggest an intrinsic developmental mechanism contributes to aortic dilation in TOF.

Prenatal diagnosis of fetal conotruncal defects by using 2D ultrasound and HD live flow combined with spatiotemporal image correlation

INTRODUCTION

To explore the diagnostic value of spatiotemporal image correlation (STIC) for different types of fetal conotruncal defects (CTDs).

METHODS

The clinical data and STIC images of 174 fetuses with CTDs diagnosed via prenatal ultrasound were analyzed retrospectively.

RESULTS

Among the 174 cases of CTDs, 58 were tetralogy of Fallot (TOF); 30, transposition of great arteries (TGA) (D-TGA, 23 cases; cc-TGA, 7 cases); 26, double outlet of the right ventricle (DORV); 32, persistent arterial trunk (PTA) (type A1, 15 cases; type A2, 11 cases; type A3, 5 cases; type A4, 1 case); and 28, pulmonary atresia (PA) (ventricular septal defect, 24 cases; ventricular septal integrity, 4 cases). Among the cases, 156 were complicated with complex congenital intracardiac and extracardiac malformations. The abnormal display rate of the four-chamber view of two-dimensional echocardiography was low. The display rate of the permanent arterial trunk was the highest (90.6%) in STIC imaging.

CONCLUSIONS

STIC imaging can be used in the diagnosis of different types of CTDs, especially in persistent arterial trunks, and thus has great value for the clinical treatment and prognosis of these defects.

D-transposition of the great arteries with right-sided pulmonary hypoplasia

Unilateral pulmonary agenesis or aplasia (UPA) in combination with congenital heart defects is rare and has not been reported in connection with transposition of the great arteries. This case demonstrated dextroposition of the fetal heart, and subsequent scans could not clearly visualize the right pulmonary artery. UPA should be considered in the workup and counseling for a family in the setting of fetal heart malposition, as there is a significant clinical impact.