Even at the early stages of gestation, the fetal face can be examined. There have been observations of the normal anatomy, such as orbits and the forehead, starting with the 12th week of gestation. However, nowadays, ultrasound equipment still cannot distinguish the soft tissues of the face, which are too thin. Yet, after the age of 14 weeks, we can easily examine the forehead, orbits, nose, lips, and ears. Recently, three-dimensional ultrasound (3D) images of the fetus can also be obtained. However, two-dimensional (2D) ultrasonographic (US) images are more easily, rapidly, efficiently, and accurately obtained. At the first stage of embryogenesis, the main part in the development of the fetal face is taken by the genetic factors. Later, the influence of the environment becomes more important. It is known that the outcome of chromosomal aberrations and of teratogenic factors is the facial malformation. Therefore, examining the facial dimorphism may get us useful hints in revealing chromosomal or genetic abnormalities. This chapter focuses on the fetal face anomalies more frequently found while performing the prenatal diagnosis. It is divided into anomalies of the orbits, nose, lip, palate, and mandible.
- fetal face
- facial malformation
- prenatal diagnosis
- congenital abnormalities
The study of the fetal face may be performed during the early stages of gestation. Depending on the gestational age, we can identify various elements of anatomy, such as the orbits or the forehead, from the 12th week. Yet, after that time, we can easily identify and study the forehead, the nose, the lips, the ears, and the orbits of the fetus . Prenatal recognition of facial abnormalities during pregnancy has many benefits. It can lead to the diagnosis of multiple genotypic syndromes and chromosomal anomalies. Also, it allows more adequate counseling and preparation of the parents. Considering that the sonographic assessment of the fetal face is a major part of the anatomic survey of the fetus, sagittal, axial, and coronal planes are used when examining the fetus.
The facial anomalies are divided into nose, orbit, lip, mandible, and palate anomalies. The US method may reveal also benign and less frequent anomalies, for example, lacrimal duct cysts, hemangiomas, and so on.
1.1. Sagittal planes
In order to assess the normality of the fetus profile, sagittal planes of the face are used (Figure 1).
One of the US parameters used to obtain an exact measurement of the position of the anterior end of the maxilla to the forehead is the angle between the surface of the palate and the frontal bone examined in a mid-sagittal view of the fetal face, called the frontomaxillary facial angle . This angle is increased in fetuses with trisomy 21, and it is believed that the reason for this is the hypoplasia or posterior displacement of the palate [2, 3].
Ears are well visualized in parasagittal scans tangential to the calvarium. In late gestation, significant details of the anatomy of the external ear can be seen.
1.2. Axial planes
1.3. Coronal planes
Evaluation of the integrity of the facial anatomy is assessed by visualizing the eyelids, orbits, lips, forehead, and nose, whose nostrils usually appear as two little anechoic areas. For these features, coronal planes are more important than the previous one (Figure 5).
1.4. Fetal face profile
One of the most common “soft sonographic sings” providing essential clues of congenital syndromes  is the deviations from the proportions normally found during a sagittal fetal face examination (Figures 6, 7). Apert or Carpenter syndromes are ruled out by examining the bridge of the nose.  The cleft lip is excluded when the normal prominent lips are visible. . As for micrognathia or prognathia, these can be noticed in the subjective abnormal appearance of the jaw .
2. The fetal eyes
From the late FT or in the early second trimester onward, we should consider the visualization of the fetal orbit and lens. The orbits will appear as echolucent circles on the upper fetal face, whereas the lens will be visualized inside these structures, as circular hyperechogenic rings. These images can be obtained during almost all scans, beginning with the late first trimester. Any deviation from the relative size might suggest congenital malformations of the orbits and lens. To assess them, coronal and especially axial planes of the fetal head are the best approach.
2.1. Anomalies of the orbits
There are at least two theories as to why hypertelorism may appear. The first theory states that there are several mechanisms causing it: the forward migration of the first half of the eyes, a midline tumor, meningoencephalocele for instance, causing the second half, or skull bones with abnormal growth vectors. The second theory links a splanchnocranium, which presents an abnormal growth, to the undeveloped bones which derive from the first branchial arches .
They resolve spontaneously in 78% of the cases by 3 months, 91% by 6 months, or during the third semester.
In order to get
During the examination of the fetal cataracts solid, either some echogenic discs or echogenicity areas within an echolucent orbit will be noticed (Figure 13), having either unilateral or bilateral opacity of the lens. Usually, the bilateral lesions are generally syndromic, with a poor prognosis; as for unilateral lesions, they are generally linked to a fetal infection. The genetic aspect of cataracts can be linked to microphthalmia.
3. The ear
The most frequent clinical characteristic in diagnosing the Down syndrome has been the short ear length. Sonographic studies implied that measurements of the short ear length could be a useful predictor of fetal anomalies. In late gestation, important details of the anatomy of the external ear became accessible. In good conditions for scanning, and using high-resolution systems, the helix, scaphoid fossa, triangular fossa, concha, antihelix, tragus, antitragus, intertragic incisure, and lobule are sometimes visualized .
4. The nasal bone and nostrils
A small nose is very commonly seen during postnatal examination of fetuses or neonates who also present trisomy 21 as well as for more than 40 other genetic problems. The nasal bone can be measured using a mid-sagittal profile for normal singleton fetuses between the 14th and 34th week of gestation. Thus, the length of the nasal bones increase from 4 mm at 14 weeks to 12 mm at 35 weeks gestation. A possible improvement in screening for trisomy 21 by examining the fetal nasal bone with ultrasound at 11–14 weeks of gestation has been considered .
4.1. Anomalies of the nose
5. The tongue
Fetal macroglossia and microglossia are associated with several chromosomal defects.
6. Anomalies of the lip and palate
The advisability of karyotype is controversial due to the low incidence of chromosomal anomalies in clefting defect. Fetuses should be delivered in a tertiary center because of the possibility of respiratory and feeding problems.
6.1. Median cleft lip
Fetuses with large tumors are best delivered by cesarean section, and an expert pediatric team must be available to intubate of the infant.
7. Abnormalities of the mandible
7.1. Robin anomalad
Robin anomaly is to be suspected when polyhydramnios is associated with micrognathia (Figure 18). Congenital heart disease occurs in 10% of affected neonates, so fetal echocardiography is recommended .
It is mandatory that a pediatrician be present in the delivery room and be prepared to intubate the infant. Karyotype should be considered .
The anatomic lesions range from ears closely opposed to the midline (synotia), agnathia, absence of the mouth to varying degrees of micrognathia and low set ears (melotia).
Otocephaly may be part of very severe malformation complexes, such as conjoined twins and holoprosencephaly .
8. The chin: Micrognathia-retrognathia or prognathia
Abnormal size of the chin, micrognathia and macrognathia, and abnormal length of the philtrum (short or long) are morphological features in numerous syndromes.
Prevalence: 1: 1500 births.