I have a 3-month old, 15 lb. son. He has excellent head control for his age, but not so well when he's tired. Do I need the infant insert?

The Infant Insert Heart2Heart is a fabulous accessory that grows with your newborn, so even if he no longer needs the extra support of the insert, you can remove the pillow and have him sit on that inside the ERGObaby Carrier, propping him at an appropriate height without confining him in the insert. This would be the best choice for your baby at this point.