I would think it depends on what the defect is. A small Atrial Septal Defect showed up on my baby's ultrasound and the fetal cardiologist told us that we are still a to deliver naturally at home. But it is definitely something to ask your doctor about.
This is a question for your doctor.
I gave birth vaginally to my son with a heart defect. I'm sure everyone's different though. I hope everything goes well for you and your baby.
I think this is a question for your Dr.