This is from Dr. Maria New's fact sheet on CAH and dex treatment (print this out and fax to your OB). I took 0.5 mg three times a day. Have your doctor call Dr. Maria New's office.  I genetic testing done (prenatal genetic testing - while I was pregnant - at 10 weeks pregnant - I had CVS test (like a amnio) and it was a boy - so I stopped the Dex treatment. The culture was sent to Dr. Maria New office and they did a DNA test for CAH and my new baby did not have CAH and was a boy. He is 6 months old now. I have two other children with CAH (boys and I had a daughter with CAH but she died at age 2 from an adrenal crisis - I took dex the entire pregnancy and she did not need surgery).

http://pedsendo.med.cornell.edu/cah/factshet.htm

Dexamethasone has been shown to be effective in preventing or
mitigating virilization or masculinization of the genitalia of
affected female fetuses. A mother must begin taking the medication
 prior to 8 or 9 weeks in order to avert labial fusion, however
clitoromegaly will be mitigated throughout the gestational period.
The recommended protocol is to begin the medication in at risk
 pregnancies as early as possible, pending a determination either
 that the fetus is a 46XY or that the fetus is an unaffected 46XX.
The dosage that we have found to be effective is calculated as follows:
0 .5 mg three times per day not to exceed 20 micrograms per kilogram
of pre-pregnancy weight.