**1.2. Axial planes**

Orbits may be visualized simultaneously, by means of an axial plane, slightly caudal to the one used to measure the biparietal diameter (**Figures 2**–**4**) [4].

**Figure 1.** (A). Normal fetal profile at 12–13 weeks. (B). Schematic representation of the scanning planes to be used for obtaining axial and coronal views of the fetal face.

**Figure 2.** Axial scan passing through the orbits of a normal second trimester fetus.

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 [1]. 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

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,

In order to assess the normality of the fetus profile, sagittal planes of the face are used

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 [2]. 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

Ears are well visualized in parasagittal scans tangential to the calvarium. In late gestation,

Orbits may be visualized simultaneously, by means of an axial plane, slightly caudal to the

**Figure 1.** (A). Normal fetal profile at 12–13 weeks. (B). Schematic representation of the scanning planes to be used for

significant details of the anatomy of the external ear can be seen.

one used to measure the biparietal diameter (**Figures 2**–**4**) [4].

obtaining axial and coronal views of the fetal face.

when examining the fetus.

92 Congenital Anomalies - From the Embryo to the Neonate

hemangiomas, and so on.

**1.1. Sagittal planes**

(**Figure 1**).

palate [2, 3].

**1.2. Axial planes**

**Figure 3.** The interocular distance (IOD) and binocular distance (BOD) are demonstrated in this scan. The lens is visible inside the orbit.

**Figure 4.** Axial scan of the lower fetal face demonstrating the upper lip and the anterior palate.

**Figure 5.** A. Coronal anterior plane in a late first trimester (FT) fetus: The lens inside the corpus vitreum B. The tip of the nose, the alae nasi, and the columna are seen above the upper lip. The nostril typically appears as two little anechoic areas.

face examination (**Figures 6**, **7**). Apert or Carpenter syndromes are ruled out by examining the bridge of the nose. [5] The cleft lip is excluded when the normal prominent lips are visible. [1]. As for micrognathia or prognathia, these can be noticed in the subjective abnormal

**Figure 6.** Sonographic pictures of fetal bossing forehead at 24 weeks of gestation. The postnatal aspect of the neonates

Congenital Abnormalities of the Fetal Face http://dx.doi.org/10.5772/intechopen.73072 95

**Figure 7.** Sagittal scan of a fetus at 13–14 weeks of gestation shows FT bossing forehead.

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.

appearance of the jaw [6].

**2. The fetal eyes**

with bossing forehead.

#### **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 [1] is the deviations from the proportions normally found during a sagittal fetal

**Figure 6.** Sonographic pictures of fetal bossing forehead at 24 weeks of gestation. The postnatal aspect of the neonates with bossing forehead.

**Figure 7.** Sagittal scan of a fetus at 13–14 weeks of gestation shows FT bossing forehead.

face examination (**Figures 6**, **7**). Apert or Carpenter syndromes are ruled out by examining the bridge of the nose. [5] The cleft lip is excluded when the normal prominent lips are visible. [1]. As for micrognathia or prognathia, these can be noticed in the subjective abnormal appearance of the jaw [6].
