Interruption of the Aortic Arch

Introduction Interruption of the aortic arch (IAA) is an uncommon ductal-dependent congenital cardiovascular malformation. It is the most severe form of aortic coarctation (AoC). Disease Definition IAA is characterized by the lack of continuity between the ascending and descending aorta. Prevalence and Epidemiology IAA accounts for 0.1% of all prenatally detected congenital heart diseases (CHDs) and 0.2% to 1% of postnatal CHDs, affecting 1 : 300,000 newborns. IAA…

Aortic Coarctation

Introduction Aortic coarctation (AoC) is a ductal-dependent heart anomaly characterized by a narrowing of the aorta. The presence of physiologic right-to-left shunts in the fetal circulation constitutes a challenge for prenatal diagnosis, making AoC one of the congenital heart diseases (CHDs) with the most common false-positive and false-negative diagnoses. Disease Definition AoC consists of a constriction on the aortic arch that causes obstruction of the blood…

Hypoplastic Left Heart Syndrome and Mitral Atresia

Introduction Hypoplastic left heart syndrome (HLHS) occurs in 0.1 : 1000 to 0.6 : 1000 live births and accounts for 2% to 3% of all congenital heart diseases (CHDs). HLHS is one of the most severe CHDs, with a high rate of perinatal death. Without treatment, it is responsible for 25% to 40% of all neonatal cardiac deaths. Disease Definition HLHS encompasses a spectrum of congenital heart malformations characterized by…

Aortic Stenosis and Aortic Atresia

Introduction Aortic stenosis (AS) affects 1.4 : 10,000 newborns. The spectrum of clinical manifestations varies widely according to the degree of valve stenosis. Disease Definition AS and aortic atresia encompass a group of congenital heart diseases (CHDs) characterized by left ventricular outflow tract obstruction. Depending on the level of the defect, these are classified as supravalvular, valvular, or subaortic obstruction. Valvular stenosis is the most frequently found form…

Pulmonary Stenosis and Atresia

Introduction Pulmonary stenosis (PS) and pulmonary atresia (PA) with intact ventricular septum have a low incidence in the fetus. In PS, there is a narrowing of the right ventricular outflow tract, whereas PA is characterized by an absent ventriculoarterial connection. The conditions are anatomically related, but the prognosis may vary substantially. Disease Definition PS refers to a narrowing of the right ventricular outflow tract secondary to…

Ebstein Anomaly and Tricuspid Dysplasia

Introduction Ebstein anomaly (EA) and tricuspid dysplasia (TD) are congenital heart diseases (CHDs) affecting the tricuspid valve and consequently all of the right heart. Although these anomalies are two different entities from an anatomic point of view, they share many pathophysiologic features. The clinical spectrum is variable depending on the degree of disruption of the valve anatomy. Prenatal forms usually belong to the severe spectrum. Disease…

Tricuspid Atresia

Introduction Tricuspid atresia (TA) is a rare form of congenital heart disease (CHD) that usually involves severe hypoplasia of the right ventricle. Prenatal diagnosis of TA and associated intracardiac and extracardiac anomalies is possible with a high degree of accuracy. Disease Definition TA is defined by the lack of connection between the right atrium and the right ventricle. The most common form is the absence of…

Atrioventricular Septal Defect

Introduction Atrioventricular septal defect (AVSD) is one of the most commonly diagnosed congenital heart diseases (CHDs) during fetal life and affects 4% to 5% of newborns with a CHD. AVSDs have a strong association with Down syndrome and frequently occur in combination with other CHDs. Disease Definition The term AVSD covers a spectrum of CHDs characterized by a common deficient separation in the atrioventricular junction. AVSD…

Ultrasound of Normal Fetal Heart

Introduction Congenital heart diseases (CHDs) are the most common severe congenital malformations, affecting 0.8% to 1% of newborns. Approximately half of the CHDs are severe defects. The overall mortality of a CHD diagnosed prenatally ranges from 25% to 35%, and about 15% of children born with a CHD die before they reach adolescence. Overall, the risk of associated chromosomal aneuploidy lies between 15% and 30%, with…

Congenital High Airways Obstruction Syndrome (CHAOS) and Bronchial Atresia

Introduction Congenital high airway obstruction syndrome (CHAOS) is a rare fetal anomaly that is associated with a high mortality (80%–100%). Prenatal diagnosis is clinically relevant in parental counseling and decision making regarding fetal surveillance, planning of fetal intervention, method of delivery, and postnatal management. CHAOS can be bilateral or unilateral (bronchial atresia). Disorder Definition CHAOS is an extremely rare condition consisting of complete intrinsic obstruction of…

Fetal Thyroid Masses and Fetal Goiter

Introduction The prenatal diagnosis of fetal goiter was first described in 1980. Advances in prenatal imaging and fetal hormonal physiology have enabled the identification of some severe but treatable disorders in the fetus. The potential benefits to the fetus of any prenatal treatment regimen must be carefully weighed against the potential risks to the fetus and the mother. Disease Definition Fetal goiter is an enlargement of…

Neck Teratoma

Introduction Fetal tumors are rare; teratomas are the most common histologic type. The neck is the most common location after the sacrococcygeal area for teratomas. The tissues found in fetal and infant teratomas are essentially the same regardless of the site of origin. A neck teratoma may be associated with neonatal mortality in 80% to 100% of cases if delivery is not managed properly. For large…

Cystic Hygroma

Introduction Cystic hygroma (CH) is a congenital lymphatic malformation. It is the most frequently observed fetal neck pathology on prenatal ultrasound (US). Disease Definition CH is an abnormality of the vascular lymphatic system, characterized by the development of distended fluid-filled spaces, typically affecting the fetal neck (80% of cases). Based on the presence of septations, it can be classified into septated or nonseptated CH . Prevalence…

Facial Dysmorphism

Introduction Facial dysmorphism is a classical feature of many syndromes, and commonly includes one or a combination of facial features such as low-set ears, hypotelorism or hypertelorism, micrognathia or retrognathia, frontal bossing, and sloping forehead. Considering some of these features are detectable prenatally, facial assessment in routine ultrasound (US) could lead to the diagnosis of chromosomal anomalies or polymalformative syndromes. Disease Definition Facial dysmorphism includes all…

Micrognathia and Retrognathia

Introduction The fetal mandible is a common site for defects caused by numerous genetic conditions and adverse environmental factors. When an anomaly in the fetal mandible is detected on ultrasound (US), the clinician should look for other anomalies in the fetal anatomy because such associations are frequent. Disease Definition Retrognathia refers to a facial malformation characterized by abnormal development of the mandible with an abnormal position…

Choanal Atresia

Introduction Congenital choanal atresia is an uncommon condition resulting from a failure of the oronasal membrane to break down. Prenatal diagnosis of choanal atresia is rarely described, and postnatal confirmation is required. However, this condition can be suspected in the presence of nose anomalies, mainly if other fetal anomalies are present. Disease Definition Choanal atresia is a congenital obstruction of the posterior nasal apertures. Prevalence and…

Orbital Defects : Hypertelorism and Hypotelorism

Introduction Orbits can be identified from 10 to 12 weeks of gestation by transvaginal ultrasound. On ultrasound evaluation, orbits appear as echolucent circles, and inside these structures lenses can be indentified as small echogenic circular structures. In normal development, ocular structures develop laterally and migrate toward the midline to reach their final position. Orbital defects are rarely diagnosed in the fetus. However, these anomalies are highly…

Cleft Lip and Palate

Introduction Orofacial clefts, which include cleft lip (CL), cleft lip and palate (CLP), and cleft palate alone (CP), include a range of disorders affecting the lips and oral cavity, and represent the most common craniofacial malformation identified in the newborn. They can occur as a part of a syndrome involving multiple organs or as isolated malformations. Disorder Definition Orofacial clefts represent all those defects involving the…

Clubfoot (Talipes Equinovarus)

Introduction Talipes equinovarus (clubfoot) is an abnormality of the foot position. It may be positional, congenital (isolated), or part of a syndrome. Clubfoot resulting from in utero positional forces, as may occur with prolonged severe oligohydramnios, multiple gestation, or breech presentation, is not a “true” clubfoot in that the deformity can usually be corrected by manual manipulation of the foot. Disease Definition Clubfoot is a foot…