Transverse septum lingual view on two-dimensional ultrasound for prenatal detection of cleft palate.

Abstract

Clefts of the lip and palate are among the most common non-lethal congenital abnormalities. Accurate antenatal diagnosis of an orofacial cleft can aid in its prognosis and management, as secondary palatal involvement is commonly associated with long-term difficulties in speech, hearing and mid-face protrusion1. Prenatal ultrasound imaging of the fetal palate has advanced in recent years and different two-dimensional (2D) and three-dimensional (3D) ultrasound techniques have been reported for visualization of the hard and soft palates1, 2. The sensitivity of 2D ultrasound for the detection of clefts of the lip and alveolus is 45–75%, however clefts involving the secondary palate are difficult to diagnose with conventional 2D ultrasound. Several studies have focused on 2D ultrasound detection of cleft palate, and different techniques have been described3, 4. Here we describe a new 2D ultrasound approach, the transverse septum lingual view, for detection of a cleft involving the hard palate following identification of an isolated facial cleft on routine ultrasound examination. We examined 11 women between 20 and 34 weeks of gestation who were referred to a regional cleft lip and palate prenatal diagnostic service (Cleft Net East, East Anglia, Addenbrooke's Cambridge University Hospital, Cambridge, UK) in 2010–2012 following suspicion of a facial cleft on an earlier routine 2D ultrasound examination. In all cases we attempted to diagnose prenatally a cleft palate using a combination of 2D and 3D ultrasound. The transverse section of the fetal face at the level of the nasal septum was obtained on 2D ultrasound: the transducer was moved parallel to the alveolar ridge plane in the cranial direction until the zygomatic arch was reached and the nasal septum was visualized in the center. In cases with a normal intact palate, it was not possible to identify the fetal tongue as the nasal and oral cavities are normally separated by the hard palate. A cleft in the hard palate was considered to be present if the fetal tongue was seen moving next to, or abutting, the nasal septum in transverse and oblique views, demonstrating continuity between the oral and nasal cavities and herniation of the tongue into the ethmoid sinus (Figures 1 and 2). All cases underwent a subsequent 3D ultrasound examination with reverse face rendering technique for confirmation of the cleft palate. In all 11 cases examined, findings in the transverse septum lingual view revealed concordance with those of the 3D reverse face view and postnatal follow-up. As there were no cases without a cleft of the hard palate, we were unable to ascertain the false-positive rate and to assess the sensitivity and specificity of our technique. It should be borne in mind that this technique requires ‘live scanning’ examination in order to visualize the fetal tongue moving through the cleft palate, which is difficult to assess on still 2D ultrasound images. We have described a simple technique to assess the integrity of the hard palate on 2D ultrasound in patients in whom a cleft lip has been detected. Visualization of the fetal tongue moving next to the nasal septum strongly suggests the presence of a gap between the oral and nasal cavities, and potentially serves as a marker for cleft palate. We believe that the transverse septum lingual view may therefore be a useful additional modality for the prenatal diagnosis of a cleft of the hard palate. However, prospective studies are necessary to validate the role of this novel 2D ultrasound marker of cleft palate in the low-risk pregnant population. C.C.L. is supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London. T.Fanelli†,M.Alberry†,W. A.Hassan† and C. C.Lees*‡ †Department of Fetal Medicine, Rosie Maternity, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; ‡Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, Du Cane Road, Imperial College Health NHS Trust, London, W12 0HS, UK *Correspondence. (e-mail: [email protected])