They also do not celebrate any holidays for the kid. Not even birthdays. That alone must be psychologically damaging even if they have an otherwise good life because they have to see all the other kids with their birthday parties and Christmas presents.
Speaking from my corner of the globe, you've got some parents, particularly those who are super hardcore about their faith in Islam, who straight-up ban birthday celebrations. Their argument? It's not a thing in our religion.
It's just so shitty to the kids. Even if you give them toys and gifts at other times of the year, it's the day every kid gets to feel special and it's taken away from them.