Anemia of Prematurity - Portal Neonatal

Prognosis:
• Pulmonary recovery: Overall reported survival varies among institutions. When all resources,
including ECMO, are provided, survival rates range from 40-69%.
• Long-term morbidity: Significant long-term morbidity, including chronic lung disease, growth
failure, gastroesophageal reflux, and neurodevelopmental delay, may occur in survivors.
MISCELLANEOUS Section 9 of 10
Special Concerns:
• Antenatal diagnosis
o Using ultrasonography, CDH may be diagnosed antenatally as early as the second
trimester. A detailed examination (level II ultrasonography) is typically necessary.
o Antenatal diagnosis allows the mother to make important decisions, including
consideration of both antenatal therapy and delivery in a facility with a neonatal
intensive care unit (NICU) that offers all possible therapies (including ECMO) for the
newborn infant.
• Antenatal surgical intervention
o In utero correction reverses pulmonary hypoplasia, pulmonary vascular abnormalities,
and left ventricular hypoplasia in the fetal lamb model.
o Human clinical trials at the Fetal Treatment Center of the University of California at
San Francisco reported survival in more than 2 dozen individual cases. However,
whether antenatal repair is more effective than repair after delivery has not been
confirmed, and risk of premature delivery is substantial. Antenatal repair is not
currently offered as a treatment option.
• In utero tracheal occlusion
o Ligation or occlusion of the fetal trachea is a new fetal treatment. The fetal lung
secretes fluid by active ion transport through gestation, and this lung fluid provides a
template for lung growth. Occlusion of the fetal trachea traps this fluid and stimulates
lung growth, either by retention of growth factors within the lung or stimulation of local
growth factors by the gentle distension provided by the fluid.
o In the fetal lamb model, this procedure reverses both pulmonary hypoplasia and
vascular abnormalities but does not correct left ventricular hypoplasia. This may be
because the mass effect of the hernia viscera on heart development is replaced by
the mass effect of the overdistended lungs. These findings have led to the use of this
technique in a small number of human fetuses.
o Tracheal occlusion is more straightforward than in utero repair of the diaphragmatic
defect and has been performed uteroscopically. More needs to be learned about this
procedure, and a randomized clinical trial is underway.
o The selection criteria for in utero surgical intervention remain controversial. Most
recently, the position of the fetal liver and the size of the fetal lungs relative to the fetal
head are promising as indicators of severe disease. Optimal timing during gestation
and length of occlusion are still under investigation.