My father has... but not me.
I lost a little weight (8 pounds?) my first trimester though, not entirely sure why. I only had mild nausea so if you are having morning sickness then you may be eating less, or eating less fatty foods, or actually throwing up some of what you eat; so that combined with the increased energy demands of pregnancy could also be responsible for your particular situation.
So... the prednisone could be masking a little weight loss depending on how you are feeling/eating during your first trimester. I think it's very typical to not gain any weight until into the 2nd trimester too - so this shouldn't be anything to be concerned about.
I lost a little weight (8 pounds?) my first trimester though, not entirely sure why. I only had mild nausea so if you are having morning sickness then you may be eating less, or eating less fatty foods, or actually throwing up some of what you eat; so that combined with the increased energy demands of pregnancy could also be responsible for your particular situation.
So... the prednisone could be masking a little weight loss depending on how you are feeling/eating during your first trimester. I think it's very typical to not gain any weight until into the 2nd trimester too - so this shouldn't be anything to be concerned about.