Gender Distinctions No Longer Ill Formed

Several people I know are soon to be parents. Now, while examples of metonymy are not unheard of when talking about the father of a child (such as he's having a baby), I think I might be stretching a little too far with this. Specifically, the context required is that the person being spoken to is more familiar with the father than the mother, or that the father is more the point of interest in this conversation. So, what I preceded to do the other day was to say that a mutual male friend was "pregnant," I guess meaning that he is an active and relevant participant in the pregnancy, since he cannot occupy the traditional role when describing one as pregnant. The typical form we expect then is with females only, which is why you usually have the question mark, as it ?Harry is pregnant and curious Spanish distinct forms, such as embarazado which don't come up so much .

Everyone seems to understand exactly that when I say Gavin is pregnant, that Gavin is going to be a father, which could be paralleled to me saying Brianna is pregnant which does imply that Brianna is going to be a mother, or parent if we want the parallel to be even closer.

I could've sworn that one of my co-workers used this usage in talking about somebody we all knew, but now I am thinking that it just reminded me of my usage, and I sort of over-wrote my memory of somebody using a more common metonym, most likely the aforementioned Harry is having a baby.