It is important that treatment is started soon after birth. The results are significantly better when treatment starts within 2 weeks after birth. If treatment is started more than 3 weeks after birth, the results are less favourable. This is because of the malleability of cartilage, which is very high at a very young age due to the level of oestrogen from the mother that is still present in a newborn baby, and which rapidly decreases after 6 weeks. Therefore, if your child is older than 6 weeks, treatment cannot be started.