**5. Lungs, diaphragm**

Based on our findings, 255 out of 351 congenital craniospinal malformations were diagnosed

We found that the sensitivity of ultrasound was high in case of the anencephaly/exencephaly (95%), spina bifida (88.89%), hydanencephaly (87.5%) and ventriculomegaly (80%) groups. However, the sensitivity of ultrasound was lower in the corpus callosum agenesis (50%),

Malformations of the facial structures are often minor anomalies, therefore, they do not cause any functional impairment. However, they can suggest chromosomal abnormalities or other, more severe congenital anomalies (malformations of the heart or brain) so diagnosing these

Facial structures to be examined are the nose, lips, ears and chin. The efficacy of prenatal ultrasound is low in case of these malformations and they are often left undiagnosed. As ultrasound techniques develop, the detection of anomalies such as cleft lip and palate (**Figure 4**) before birth is getting more accurate, reaching a sensitivity of 14–25% [19, 20]. 3D technique

In our study, only 43 out of 135 face malformations were diagnosed prenatally (31.85%). We found that cleft lip and palate was detected with the highest sensitivity (53.33%), while no

**Figure 4.** Cleft lip. The detection of anomalies such as cleft lip and palate before birth is getting more accurate.

Congenital malformations of the cardiovascular system are the most common malformations with a birth prevalence of 8:1000. Half of these malformations are severe and life-threatening

choanal atresia cases and only 9.09% of micrognathia cases were found.

proved to be more effective in assessing the facial structures of the fetus [21].

microcephaly (25%) and Arnold-Chiari malformation groups.

prenatally (72.65%).

8 Congenital Anomalies - From the Embryo to the Neonate

minor anomalies is important.

**4. Cardiovascular system**

**3. Face**

Malformations of the lung are rare anomalies, but diagnosing them prenatally is still important, especially to determine appropriate postnatal management. At 18 weeks of pregnancy, the lungs can be visualized around the heart, filling two-third of the thorax. The quantity of the amniotic fluid has an important role in the development of the lungs. Therefore, in severe oligohydramnios the lungs become hypoplastic (Potter-sequence).

Cystic malformations of the lungs can be separated into three groups: solitary and multiplex cystic anomalies and congenital cystic adenomatoid malformation (CCAM). The latter is a multicystic hamartoma that is usually confined to only one lobe. 47–80% of all lung malformations are CCAMs with a prevalence of 0.3–0.9/10,000 [31–33]. Ultrasound detection depends on the size of the cyst: Type I: 10–20 mm, Type II: 5–10 mm, Type III: small, not detectable. If the anomaly is large it may dislocate the mediastinal structures, causing polyhydramnios through the compression of the esophagus. It is often associated with other malformations such as cardiovascular, urogenital, and skeletal anomalies or hydrocephalus.

examination is justified in these fetuses as omphalocele is associated with other malformations and chromosomal abnormalities in more than half of the cases. The smaller the defect is, the higher the risk of aneuploidy is. When there is no associated malformation, the pregnancy can

Congenital Fetal Anomalies and the Role of Prenatal Ultrasound

http://dx.doi.org/10.5772/intechopen.71907

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Abdominal wall malformations were diagnosed with a high sensitivity in our study. All gastros-

The fetal stomach can be visualized with ultrasound after 14 weeks. During the second and third trimester, the liver, gall bladder, spleen and intestines can all be examined with ultrasound in most cases. When the stomach cannot be seen it may suggest malformations such as esophageal atresia, diaphragmatic hernia, abdominal wall anomalies or neurological problems. When the filling of the stomach is not visualized during the examination, the ultrasound

Esophageal atresia is the absence of a part of the esophagus. The atresia is positioned higher than the trachea bifurcation in 85%, and a tracheoesophageal fistula is present in 90% of the cases. The birth prevalence of this malformation is around 1:3000. Signs on the ultrasound are polyhydramnios and the absence of the filling of the stomach. However, when a fistula is present, the stomach is filling, hence the low prenatal detection rate (10–40%) and late, third trimester diagnosis [14, 16, 34]. Later on, at around 24 weeks of pregnancy, the dilatation of the proximal end may be seen. About half of the cases are associated with other malformations, aneuploidy in 20%, growth retardation in 40% and most often with cardiovascular anomalies. Therefore, performing echocardiography and cytogenetic examination

The appearance of the intestines changes with the development of the fetus. Increased echogenicity of the fetal intestines can be a normal variant, but can also appear after the ingestion of blood. An increased echogenicity (as high as the bones) may appear in gastrointestinal malformations, Down-syndrome, cystic fibrosis or congenital infections (such as cytomegalovirus)

Duodenal atresia may occur due to a real atresia, membranous closure or compression (annular pancreas) of the duodenum. The incidence of this condition is around 1:6000–1:10,000 birth. One-third of the cases are associated with Trisomy 21 and 50% develop as part of multiplex malformations. The specific ultrasound finding for duodenal atresia is the "doublebubble" sign. The two bubbles are the distended stomach and proximal duodenum. Usually polyhydramnios also appears. Echocardiography and cytogenetic examination is needed to

Intestinal atresia only affects the small intestines in 95% of the cases with an incidence of

chisis (12/12) and most of omphalocele (25/33, 75.76%) cases were diagnosed antenatally.

be carried to term [40].

**7. Gastrointestinal system**

has to be repeated [5, 36].

is important [5, 36, 41, 42].

detect the associated anomalies [5, 36].

[5, 36, 43].

1:10,000 live birth.

In pulmonary sequestration, the hamartoma usually gets its blood flow from the systemic circulation, either from the abdominal or the thoracic aorta. Most often small cysts (Type III) can be seen on the ultrasound, but it is important to prove the hamartomas connection to the systemic circulation. The intralobular form is more prevalent, but is less likely to get diagnosed. 90% of the extralobular cases are located in the left lower lobe and it is easier to detect [33, 34].

In diaphragmatic hernia, abdominal organs get through a defect of the diaphragm to the thorax. The incidence of this malformation is around 1:3700. 90% of the hernias are present on the left side. The defect itself, abdominal organs in the thorax and mediastinal shift can be detected with ultrasound. Pulmonary hypoplasia can also develop in severe cases due to the volume expansion in the thorax [5, 35].

Malformations of the lungs were detected with a 52.94% sensitivity in our study, while diaphragmatic hernia cases were diagnosed with ultrasound in 86.79% of the cases.
