From the Research
Fetal coarctation of the aorta in utero is a potentially life-threatening condition that primarily affects cardiac development and circulation, causing significant hemodynamic changes, and prenatal diagnosis is crucial for planning immediate postnatal care. The main effects of fetal coarctation of the aorta include left ventricular hypertrophy as the heart works harder to pump blood through the narrowed aorta, and potential right ventricular dominance due to blood flow redistribution 1.
Key Effects of Fetal Coarctation
- The fetus may develop increased right-to-left shunting across the foramen ovale and ductus arteriosus, which helps maintain systemic circulation despite the obstruction.
- This condition can result in decreased blood flow to the lower body, potentially affecting growth of the lower extremities.
- In severe cases, hydrops fetalis may develop due to heart failure.
- The fetus often remains stable during pregnancy because the placental circulation and patent ductus arteriosus provide alternative pathways for blood flow, but rapid deterioration can occur after birth when these pathways close.
Importance of Prenatal Diagnosis
Prenatal diagnosis is crucial for planning immediate postnatal care, as prostaglandin E1 infusion may be needed after birth to maintain ductal patency until surgical correction can be performed 2. The severity of effects depends on the degree of narrowing and associated cardiac anomalies. According to the most recent study, coarctation of the aorta occurs in 0.3 per 1000 live births and accounts for 6-8% of all infants with congenital heart defects 1.
Management and Outcomes
Neonates with severe coarctation of the aorta may be completely asymptomatic at birth, as the ductus arteriosus can provide flow to the lower body, but those who are not diagnosed prenatally may be diagnosed only after constriction of the ductus arteriosus, when they present in cardiogenic shock, with a higher risk for mortality and morbidity relative to those diagnosed prenatally 1. Despite the increasing practice of universal pulse oximetry screening, many cases with significant coarctation of the aorta still go undiagnosed in the newborn period. Therefore, prenatal diagnosis and planning for immediate postnatal care are essential to improve outcomes in fetuses with coarctation of the aorta.