Hi Lena,
Thal intermedia is a bit complicated cause you can not compare two patients as every case is totally different than the other. You can find intermedias who start transfusion very early in life and others may not tranfuse at all. So it is not black and white, but there are many shades of gray in dealing with intermedias.
As for my son's case, the decision of transfusion is associated with growth. Our hematologist told me that as long as his growth is within the normal range for his age, she will not need to transfuse him. She commented that his body needs have adapted to the low Hb, but this is ''as of now'' which means that this does not gurantee that the future will be the same. Therefore, continous checking and monitering is so important (can not imagine how is that very stressful on parents because you are always waiting for the unknown)
As for hydroxyurea, it is also a personal expierence of the patient because the reaction to the hydroxy differs from one person to the other. Tuning the dose is so important, also some react from the beginning of using it and others take time, that is why it is agreed that it can take up to 9 months for hydroxy to work for some patients and in others is could take only weeks.
Also the increase differs, but it was found that it can increase the hb by 2 grams which is considered very good. Some patients can react positivley to hydroxy for so long time (one of my hematologist patients has been taking hydroxy for 18 years now and married with two children) and other patients just stop reacting to it after a while as in the case of little Olivia (Katheleen's daughter) who was doing good for her for two years and then it had no significant effect on her HB
So actually there is no rule with thal intermedia, but all what you must ensure is normal growth and avoiding bone deformity
manal