When Linda found out she was pregnant with Benjamin, then Ginny, the doctor immediately put her on Dex. As soon as they were able to do an amnio to determine the gender and if the baby had CAH, she was either taken off the dex (if it was a boy with or without CAH, or of it was a girl without CAH) or remained on it otherwise. Of course Benjamin turned out to not have CAH, but Ginny did.