**4.4. Congenital lobar emphysema**

Congenital lobar emphysema (CLE) is a rare congenital malformation and sometimes is detected by prenatal ultrasonography. Lung lesions have increased echogenicity and/or a cystic appearance and usually can be differentiated from other congenital lung lesions [70]. A chest mass may even disappear on prenatal ultrasound and become apparent again on postnatal evaluation [70]. Predictors of severe respiratory distress or mortality include polyhydramnios, fetal hydrops, and lung to thorax transverse area ratio (L/T value) of less than 0.25 [70]. Approximately 25% of cases present at birth, 50% by 1 month of age, and nearly all by 6 months of age. Infants typically have tachypnea and increased work of breathing and often have cyanosis. Recurrent pneumonia or poor feeding with failure to thrive are less frequent presentations that may occur in milder forms [70].

#### **4.5. Pulmonary agenesis**

Any fetus with suspected bilateral pulmonary agenesis should have a detailed sonographic assessment to confirm the diagnosis. If the diagnosis is made till periviable pregnancy, the pregnancy termination is an option. If the diagnosis is made at a later gestational age, the delivery should be planned without monitoring for fetal distress [16].
