Tetralogy of fallot

Dear doctor,

I underwent 2D ultrasound scan, which corresponds to 23 to 24 weeks fetal maturity.
The impression given in the report is as below.
OVERRIDING OF THE AORTA OVER THE INTER-VENTRICULAR SEPTUM WITH A PERIMEMBRANOUS V.S.D WITH MILD PULMUNORY STENOSIS - T.O.F

PULMUNORY ARTERY IS SMALL IN SIZE - 3.5MM
AORTIC ROOT DIAMETER - 6.2MM

My question is, as there is a time of 3.5 months for the baby to be born, can these problems set right in the womb itself or over time? or does this need surgical intervention? Also, please tell me your view on the severity of the defect taking into consideration the above report parameters.

Thanks in advance.

[Jeffrey R Boris, M.D.]

Dear Padmashri,

Tetralogy of Fallot is a congenital heart defect that has four classic findings:  1) a ventricular septal defect (VSD), 2) aortic override of the ventricular septum, 3) pulmonary stenosis (obstruction of the pulmonary outflow tract), and 4) right ventricular hypertrophy (thickening of the right ventricle).  It does not spontaneously resolve, and definitely requires surgical intervention to improve the lifespan and quality of life of these children.  Unfortunately, I cannot tell you much more about the severity of the defect based on the limited amount of information that you have given me.  The fact that the pulmonary stenosis is mild is probably a good thing.  I cannot estimate how small the pulmonary artery is in relation to the rest of the size of the baby, however, which means that I cannot say more about the severity.  

Tetralogy is typically repaired between ages 2 and 6 months, with complete repair occurring at that time.  Occasionally, due to more complicated cardiac anatomy, a staged approach may need to be done.  This would include a shunt placed between the aorta and the pulmonary artery to increase pulmonary blood flow and allow more time for cardiac growth followed by a complete repair and shunt takedown at a later time.