Tetralogy Of Fallot

I just found out my daughter has TOF and I am 28 weeks. My first daughter was born at 39 weeks at 6lbs 1oz, and this one is planned to be born at 39 weeks via csection as well, but I'm scared of the possibility of going into labor early and her being too small for surgery. She is already measuring 1-2 weeks behind in the 2% percentile. Anyone with TOF babies? Surgery right at birth? We should be able to wait until 3-4 months old for surgery but worst case is at birth of course.