Fetal aortic coarctation: A combination of third-trimester echocardiographic parameters to improve the prediction of postnatal outcome

Prenatal Diagnosis and Postnatal Outcomes of Persistent Left Superior Vena Cava Associated With Mild Narrow Aorta: A Cohort Study

PURPOSE

To explore prenatal ultrasonic features and prognosis of the persistent left superior vena cava (PLSVC) complicated with mild narrow aorta.

MATERIALS AND METHODS

A retrospective study was conducted involving 1348 fetuses diagnosed with PLSVC prenatally between January 2016 and December 2019. Forty-five fetuses with PLSVC associated with mild narrow aorta were selected from the cohort as the study group and 79 fetuses with isolated PLSCV were recruited randomly as the control group. All clinical and ultrasound results, including images and parameters of cardiac structures, were reviewed retrospectively. General conditions, ultrasound (US) measurements, and fetal prognosis were compared between the groups.

RESULTS

Aorta valve diameter (AOD), Z-score of aorta valve (AODz-score), aortic isthmus diameter (AOIsD), and pulmonary diameter (PAD)/AOD were significantly different in study group than control group no matter in the second or third trimester. Thirty-eight fetuses in study group were born with favorable outcomes after long-term follow-up. A total of 13.16% (5/38) remain mild narrow aorta and 3 of them showed smaller left ventricle after 3 years follow up. Prenatal AODz-score in infants remains mild narrow aorta after 2 years aged was higher than ones' aorta return to normal (P = .01), especially when AODz-score >1.725. Moreover, when prenatal ratio of AOIsD/left subclavian artery was <1.12, it was more likely that the aorta would remain mildly narrow at age 2.

CONCLUSION

Fetuses diagnosed with PLSVC with mild narrow aorta had favorable prognosis. AODz-score and AOIsD/left subclavian artery may be two predictors that reveal the risk of a mildly narrowed aorta remaining after birth.

Fetal cardiac magnetic resonance imaging of the descending aorta in suspected left-sided cardiac obstructions

Background

Severe left-sided cardiac obstructions are associated with high morbidity and mortality if not detected in time. The correct prenatal diagnosis of coarctation of the aorta (CoA) is difficult. Fetal cardiac magnetic resonance imaging (CMR) may improve the prenatal diagnosis of complex congenital heart defects. Flow measurements in the ascending aorta could aid in predicting postnatal CoA, but its accurate visualization is challenging.

Objectives

To compare the flow in the descending aorta (DAo) and umbilical vein (UV) in fetuses with suspected left-sided cardiac obstructions with and without the need for postnatal intervention and healthy controls by fetal phase-contrast CMR flow. A second objective was to determine if adding fetal CMR to echocardiography (echo) improves the fetal CoA diagnosis.

Methods

Prospective fetal CMR phase-contrast flow in the DAo and UV and echo studies were conducted between 2017 and 2022.

Results

A total of 46 fetuses with suspected left-sided cardiac obstructions [11 hypoplastic left heart syndrome (HLHS), five critical aortic stenosis (cAS), and 30 CoA] and five controls were included. Neonatal interventions for left-sided cardiac obstructions (n = 23) or comfort care (n = 1 with HLHS) were pursued in all 16 fetuses with suspected HLHS or cAS and in eight (27%) fetuses with true CoA. DAo or UV flow was not different in fetuses with and without need of intervention. However, DAo and UV flows were lower in fetuses with either retrograde isthmic systolic flow [DAo flow 253 (72) vs. 261 (97) ml/kg/min, p = 0.035; UV flow 113 (75) vs. 161 (81) ml/kg/min, p = 0.04] or with suspected CoA and restrictive atrial septum [DAo flow 200 (71) vs. 268 (94) ml/kg/min, p = 0.04; UV flow 89 vs. 159 (76) ml/kg/min, p = 0.04] as well as in those without these changes. Adding fetal CMR to fetal echo predictors for postnatal CoA did not improve the diagnosis of CoA.

Conclusion

Fetal CMR-derived DAo and UV flow measurements do not improve the prenatal diagnosis of left-sided cardiac obstructions, but they could be important in identifying fetuses with a more severe decrease in blood flow across the left side of the heart. The physiological explanation may be a markedly decreased left ventricular cardiac output with subsequent retrograde systolic isthmic flow and decreased total DAo flow.