What is the ideal timing of repair of av canal defect with tetralogy of fallot in a child 4 months old delivered premature , growing slowly ?

Heart defect: Some institutions use the criteria of 10-12 lbs before operating unless the infant is critical.

Ideally 4-6 m: Ideally repair is carried out at 4-6 months of age. However, some babies may be very symptomatic requiring repair earlier. Many surgeons may prefer the baby to be 4-5 kg (9-12 lbs) before repair. Considering preemies start with a low birth weight and may have poor weight gain, then repair may be at an older age still within the first year of life. Caloric intake should be optimized until surgery.