Girls, hello everyone! Could you please advise me?

Girls, hello everyone! Could you please advise me? I recently had my second ultrasound. The sonographer said that my little one is skinny, like skin to bone, has anyone experienced this? I don't know what it could be from, I seem to eat normally, but maybe from toxemia from which I just recovered. I don't even know what to do next, I can't overeat either, he won't come out, I take vitamins...