8.1 Cleft Lip and Palate
Description and Clinical Features
Cleft lip is a congenital defect in the upper lip that is usually laterally located and often extends into the ipsilateral nostril. It often involves the anterior maxilla as well. Cleft palate is a defect of the soft and hard palate. Cleft palate can occur on its own or in combination with cleft lip. Cleft lip and/or cleft palate may be unilateral or bilateral or may be a single large defect in the midline. Midline defects are often associated with intracranial anomalies, particularly holoprosencephaly. Unilateral or bilateral cleft lip and/or cleft palate can occur as a component of various syndromes, including genetic and nongenetic ones and those related to abnormal karyotypes. Anomalies are found in association with isolated cleft lip in about 20% of cases. Among fetuses with combined cleft lip and palate, close to 50% have other structural anomalies, and almost half of those with anomalies have aneuploidy.
Cleft lip and/or cleft palate is found in approximately one per 1,000 live births, with 50% having both cleft lip and cleft palate, 20% having isolated cleft lip, and 30% isolated cleft palate. Males are affected more frequently than females, accounting for 60% to 80% of cases. In the absence of other anomalies, the prognosis is excellent. When other anomalies are present, the prognosis is related to the severity of these anomalies.
The presence of cleft lip and/or cleft palate in utero can cause impaired fetal swallowing. Thus, these pregnancies may be complicated by polyhydramnios.
Unilateral cleft lip appears on grayscale (Figure 8.1.1) and 3D (Figure 8.1.2) ultrasound as a defect in one side of the upper lip extending into the ipsilateral nostril. Amniotic fluid outlines the defect. When a cleft palate is also present, the groove extends deeper than with cleft lip alone. With bilateral cleft lip, defects are seen on both sides of the upper lip, each extending into the ipsilateral nostril (Figure 8.1.3). The intervening midline portion of the upper lip and maxilla will sometimes protrude or become everted, an appearance called maxillary prominence (Figure 8.1.4). Midline cleft lips appear as central defects in the upper lip extending into the base of the nose and often into both nostrils (Figure 8.1.5). As with a unilateral cleft lip, when cleft palate accompanies midline cleft lip, the defect appears deeper. Diagnosis of cleft lip, whether unilateral, bilateral, or midline, is often facilitated by the presence of polyhydramnios, allowing amniotic fluid to surround the fetal face for better sonographic visualization.
The prenatal diagnosis of cleft palate in the absence of cleft lip is sometimes possible in the third trimester using 3D ultrasound, but imaging may be difficult due to shadowing from the maxilla (Figure 8.1.6).
Because of the association with other anomalies, a careful fetal survey should be performed when a facial cleft is identified.
Figure 8.1.3 Bilateral cleft lip. A: Image of bilateral clefts (arrowheads) in upper lip (arrows). B: 3D in same fetus showing bilateral clefts (arrowheads).
Description and Clinical Features
Macroglossia is an abnormally large tongue. It can occur in fetuses of diabetic mothers as well as in fetuses with various syndromes, including Beckwith–Wiedemann (a syndrome characterized by organomegaly and omphalocele), trisomy 21, and congenital hypothyroidism. The enlarged tongue protrudes from the mouth and may interfere with swallowing, thus causing polyhydramnios. Some anomalous fetuses may have persistent protrusion of the tongue for reasons other than macroglossia, including abnormal muscle tone, an oral mass displacing the tongue, or an abnormally small mouth.
When macroglossia is present, the tongue persistently protrudes from the fetal mouth (Figure 8.2.1). When the tongue is seen protruding from the mouth, careful examination of the fetus is warranted to determine whether the tongue itself is enlarged or the tongue is protruding due to abnormal tone or displaced by an oral mass or secondary to a small mouth (Figure 8.2.2). Once the diagnosis of macroglossia is made, the fetus should be assessed for other anomalies, such as omphalocele, which is associated with Beckwith–Wiedemann syndrome (Figure 8.2.3), or signs of trisomy 21 (Figure 8.2.4).
Figure 8.2.1 Macroglossia. Sagittal image of face demonstrating large tongue (arrow) protruding anteriorly between upper (U) and lower (L) lips.
Figure 8.2.2 Protruding tongue due to small mouth. 3D image of face in a fetus with achondrogenesis showing protrusion of the tongue (arrow), which is pushed outward because the mouth is too small in fetuses with this condition.
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