Hi Sandra,

From the point of view of the parent, I agree that every little detail about our children is endlessly fascinating.  So, if I were in your shoes, I might be tempted to ask about the ACTH stim test, too.  But, from the point of view of the doctor, my feeling is that the ACTH is not really necessary to inform treatment, in a situation like this.   

In my opinion, the ACTH is proabably the best test to use if you are still trying to establish a diagnosis of CAH, and still trying to determine which enzyme is blocked....21-hydroxylase, 11-hydroxylase, etc.  In the case of the baby being treated prenatally, that information is already known before the baby is born.  So, unless the results are in doubt, there really shouldn’t be the need for an additional test.

After the baby is born, what needs to be confirmed is whether the baby will need treatment with only cortisol medications, or cortisol AND florinef.  Again, the doctors should already have a pretty good idea prior to birth, what the scenario might be, since they will already know the baby’s genotype.  And they will also have had experience with the older sibling with CAH. 

True, phenotype is not always true to genotype and siblings may not present in exactly the same way....but the point is that---even if one child ends up presenting more like a salt-waster while the other does not---it is not the results of the ACTH stim. test that will determine the need for florinef....it is the electrolyte and renin levels.  And that is gotten from a regular blood draw...not the stim test. 

Neither will the results of the ACTH determine the amount of cortisol medication that the child will need.  So---practically speaking---nothing much will really change, even if a stim test is done.    

I remember you had asked and posted about this a while ago.  From what I could tell, none of these babies treated prenatally underwent the stim test after they were born. That makes sense to me, but it would be interesting to hear why these doctors presumably didn’t think it was necessary.....this is just my two cents.  I would guess  that you have already asked your own endo about this by now....what does he/she think?

http://www.congenitaladrenalhyperplasia.org/mb/index.php?page=19&forum=main

P. S. You must be getting close to your due date now...hope all is going well!