Boys Petit Bateau pajamas 14 ans years

I bought these for my son while visiting in France. I just don’t remember what size he was when he wore these because he only wore them a few times. Possibly a size 12. Unstretched, they are a 23 inch waist and stretched. They go all the way to 40 inches. There’s so much stretch in these. The inseam is approximately 27 inches