Twins with compensatory hypothroidism

Hi , Thanks for answering my question re: twins with congenital hypothroidism.  I have since got the results from the heel ***** and their thyroid was normal at birth and that they actually developed compensatory primary hypothroidism after having numerous infections - Rota virus, Adeno ? virus , gasenteritis they had both spent app. 1 1/2 months going in and out of hospital. They were born at 38 weeks. Theie weights were 6 lb 10 oz and 5 lb 14oz.  They both have developmental delays.  I can't seem to find much information on compensatory hypothroidism or any other kids that have it .  I am just wondering what to expect, I read somewhere for every month they were undiagnosed their IQ is effected between 3 to 5 points per month.  Is this true and what else can I expect.