Prenatal Diagnosis of Oral Clefts

Abstract

equipment and technique, craniofacial malformations of the fetus are now identifiable. Oral clefts are the most common facial malformation. The incidence of oral cleft has been estimated to be about 1 per 1,000 live births [1]. The antenatal diagnosis of facial clefts allows for adequate counseling and planning for prenatal care and delivery. The first antenatal ultrasound diagnosis of cleft lip and palate was reported in 1981 [2]. Two cases were reported in the third trimester. Recently, there have been reports of antenatal diagnosis as early as 12 weeks of gestation by transvaginal ultrasound [3]. Figure 2.1 shows a transvaginal ultrasound depicting a cleft lip at 13 weeks of gestation. The technique for early diagnosis of cleft lip and palate has been established [4]. Two planes of the fetal face are obtained. In the frontal plane, disruption of the normal midfacial architecture, with absence of the maxillary ridge normally seen slightly anterior and inferior to the orbits can be demonstrated. Also, broadening of the nasal cavity is noted. In the coronal plane, a soft tissue mass projecting anteriorly from the midline nasal septum below the nose is seen. Once an oral cleft has been diagnosed by ultrasound,a complete anatomical survey is warranted since there have been approximately 350 syndromes, including chromosomal abnormalities, associated with facial clefting [5]. Nyberg et al. suggested an ultrasound classification for oral clefts which describes five types [6]. Type 1 includes an isolated cleft lip without palate (Fig. 2.2). Type 2 includes unilateral cleft lip and palate. Type 3 is bilateral cleft lip and palate (Fig. 2.3). Type 4 is the median cleft. Type 5 refers to clefts associated with amniotic bands or limb-body-wall complex. The detection rate for prenatal diagnosis of oral clefts is dependent on factors such as the experience of the operator, indications for the studies, i.e., risk factors, and gestational age at the time of the study. In addition, in some prenatal ultrasound laboratories, imaging of the fetal face is done routinely, whereas in other laboratories this is not done. Examination of the fetal face in not currently included in the guidelines Prenatal Diagnosis of Oral Clefts